Answer:
D
Explanation:
There are only 2 ways to explain this.
distance
and brightness caused by what it is burning.
A is true but it is not the explanation of why it is true.
B this is actually not true. Other stars would burn much more.
C It is not the largest star. In fact it is in the lower middle.
D is the answer. 93 million miles as these things go, is not every much.
Answer:
I did this and the right answer was D
Explanation:
Which of the following is a testable hypothesis?
A. If I brush my teeth, I will get fewer cavities than if I don't brush my
teeth.
B. Green toothpaste tastes better than blue toothpaste or red
toothpaste.
C. Smart, careful, healthy people always brush their teeth.
D. It's wrong to not brush your teeth before you have an important
conversation with someone.
Answer:
If I brush my teeth, I will get fewer cavities than if I don't brush my teeth.
Explanation:
apex
Which one of the following is a decomposition reaction?
O A. N2 (9) + 3H2 (9) - 2NH3 (9)
O B. 4Fe (s) + 302 (9) - 2Fe203 (s)
O C. 2LIOH (s) + CO2 (g) - Li2CO3 (s) + H20 ()
O D. K2CO3 (s) - K20 (s) + CO2 (g)
Answer:
d
Explanation:
the answer because decomposition means breaking down or taking apart
Answer:
l
Explanation:
PLZZZ HELP The normal range of blood glucose is 70–120 mg/dL. A person has a blood glucose level of 170 mg/dL. Based on your knowledge of the endocrine system and hormones, explain the likely cause for the person's condition.
Answer:
Insulin and glucagon are the hormones that cause blood glucose (blood sugar) preserved in a narrow range. The pancreas serves as the central part of this process. Secreted by the pancreas are both insulin and glucagon. Determined by the production of insulin and glucagon, people can find out whether someone may have diabetes, hypoglycemia, low blood pressure, etc. Insulin or glucose can be prescribed to victims of those listed issues, it is mostly used to balance out the level of glucagon and insulin to try to stop the problem.
Odd one out:
a) CH3COOH
c) CuSO4
b) NaOH
d) H2SO,
what is the wavelength of a wave with a velocity of 50 m/s and a frequency of 5Hz
A 250 m
B 0.1 m
C 10m
D 0.01 m
Answer:
C. 10 m
Explanation:
The speed of a wave v = λf where λ is the wavelength and f the frequency of the wave.
Making λ the subject of the formula we get
λ= v/f
f= 5 Hz
v= 50 m/s
λ= 50 m/s÷ 5 Hz
=10 meters
Answer:
C. 10 Meters
Explanation:
A P E X
6. Which of the following statements correctly describes what happens to the diaphragm during an
inhalation, when the lungs inflate?
O A. The diaphragm returns to its resting state.
O B. The diaphragm contracts and flattens.
O C. The diaphragm only moves during exhale.
O D. The diaphragm expands.
Answer:
O B. The diaphragm contracts and flattens.
Explanation:
The diaphragm is a skeletal striated muscle that separates the abdominal cavity from the thoracic cavity, has a dome shape and plays a key role in breathing. Locate near the lumbar vertebrae, the lower ribs and the sternum and can be divided according to its location into three parts: sternal, costal and lumbar.
During inhalation, the diaphragm contracts and flattens, reducing the pressure inside the chest and compressing the viscera of the abdomen, which facilitates the entry of air into the lungs.
At the expiration, the inverse process occurs: it relaxes and rises, increasing the pressure inside the chest and expelling air from the lungs.
Given pH = 3.50 Find: [H3O+] and [OH-] Is this acidic, basic or neutral?
Answer:
Explanation:
Given parameters:
pH = 3.50
Unknown:
concentration of [H₃0⁺] = ?
concentration of [OH⁻] = ?
Solution:
In order to find the unknown, we use some simple expressions which best explains the pH scale and the equilibrium systems of aqueous solutions.
pH = -log₁₀[H₃O⁺]
[H₃O⁺] = inverse log₁₀ (-pH) = [tex]10^{-pH}[/tex] = [tex]10^{-3.5}[/tex]
[H₃O⁺] = 3.2 x 10⁻⁴moldm⁻³
For the [OH⁻]:
we use : pOH = -log₁₀ [OH⁻]
Recall: pOH + pH = 14
pOH = 14 - pH = 14 - 3.5 = 10.5
Now we plug the value of pOH into pOH = -log₁₀ [OH⁻]
[OH⁻] = [tex]10^{-pOH}[/tex]
[OH⁻] = [tex]10^{-10.5}[/tex] = 3.2 x 10⁻¹¹moldm⁻³
The solution is acidic as the concentration of H₃0⁺ is more than that of the OH⁻ ions.
When 9.6 grams of NaBr are dissolved in enough water to create a 165 gram solution what is the concentration expressed as a percent by mass
Answer:
5.8 %
Explanation:
% by mass = (mass of solute/mass of solution) × 100 %
Data:
Mass of NaBr = 9.6 g
Mass of solution = 165 g
Calculation:
% by mass = (9.6 g/165 g) × 100 % = 5.8 %
Answer:
The concentration of sodium bromide solution as a percent by mass is 5.82%.
Explanation:
Percent by Mass (w/w %) :
The percentage mass or fraction of mass of the of solute present in total mass of the solution.
[tex]w/w\%=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 100[/tex]
Mass of solute that is sodium bromide = 9.6 g
Mass of the solution prepared = 165 g
The concentration of solution as a percent by mass:
[tex]\frac{9.6 g}{165 g}\times 100=5.82\%[/tex]
what are the 4 phases of matter in order of increasing engery content?
Answer:
plasma,gas, liquid, solid
Explanation:
Plasmas are hotter than gases and so have more kinetic energy, next is gas, then liquid and finally a solid.
Answer:
the four phrase are plasma, liquid , gas , and solid
Explanation:
Which is the most likely way an automotive engineer would use chemistry
Final answer:
An automotive engineer would most likely use chemistry to design and improve automobile catalytic converters, ensuring efficient combustion and reduced toxic emissions. They also work on reformulating gasoline to meet environmental standards and improve engine performance.
Explanation:
The most likely way an automotive engineer would use chemistry is through the design and development of automobile catalytic converters. Scientists have engineered catalytic converters to significantly reduce the toxic emissions resulting from gasoline burned in internal combustion engines. By implementing a blend of catalytically active metals, these converters facilitate the complete combustion of carbon-containing compounds into carbon dioxide, while also diminishing the output of nitrogen oxides.
Another aspect of chemistry in automotive engineering involves the reformulation of gasoline. Removing substances like tetraethyllead, which hampers exhaust catalysts, and decreasing the presence of highly volatile and unsaturated hydrocarbons are critical to reduce photochemical smog and increase engine efficiency.
A substance added in The final stages to remove sulphur from coal is
A substance used to remove Sulphur from coal is a desulfurizing agent, commonly a limestone slurry. It chemically reacts with the Sulphur emissions, creating less harmful substances like Gypsum.
Explanation:A substance used in the final stages to remove Sulphur from coal is called a desulfurizing agent or a scrubber. One technique includes the use of a limestone slurry, which reacts chemically with the sulphur emissions and converts them into less harmful substances, such as gypsum. Gypsum, or calcium sulfate, is a beneficial byproduct because it can be used in the manufacture of wallboard and other building materials. Thus, the process not only removes pollutants like sulfur from the coal but also creates a valuable byproduct.
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The combustion of methane, CH4, releases 890.4
kJ/mol. That is, when one mole of methane is burned,
890.4 kJ are given off to the surroundings. This means
that the products have 890.4 kJ less than the reactants.
Thus, AH for the reaction = - 890.4 kJ. A negative symbol
forAH indicates an exothermic reaction.
CH (g) + 20 (g)> CO2 (g) + 2 H0 (1); AH = - 890.4 kg
a) How much energy is given off when 2.00 mol of CH,
are burned?
b) How much energy is released when 22.4g of CH. are
burned?
Answer:
[tex]\boxed{\text{a) 1.78 MJ; b) 1.25 MJ}}[/tex]
Explanation:
[tex]\rm CH$_4$ + 2O$_2 \longrightarrow \,$ CO$_2$ + 2H$_2$O; \Delta H = - 890.4 \text{ kJ}$\cdot$\text{mol}$^{-1}$[/tex]
a) Energy from 1 mol
[tex]\Delta_{\text{c}}H^{\circ} = \text{2.00 mol} \times \dfrac{\text{-890.4 kJ}}{\text{1 mol}}=\text{-1780 kJ} = \textbf{-1.78 MJ}\\\\\text{The reaction gives off } \boxed{\textbf{1.78 MJ}}[/tex]
b) Energy from 22.4 g
(i) Convert grams to moles
[tex]n = \text{22.4 g } \times \dfrac{\text{1 mol }}{\text{16.04 g}} = \text{1.399 mol}[/tex]
(ii) Convert moles to energy
[tex]\Delta_{\text{c}}H^{\circ} = \text{1.399 mol} \times \dfrac{\text{-890.4 kJ}}{\text{1 mol}}=\text{-1250 kJ} = \textbf{-1.25 MJ}\\\\\text{The reaction releases } \boxed{\textbf{1.25 MJ}}[/tex]
an
What happens to a molecule of liquid water when hydrogen bonds between atoms are broken?
O The liquid turns to a gas.
The liquid turns to a solid.
The liquid gains hydrogen atoms.
The liquid does not otherwise change.
Answer:
Your Answer is A: The Liquid turns to gas
Explanation:
To break hydrogen bonds you must add heat. When you add heat to water it turns into a gas. So therefore your answer is The Liquid Turns To A Gas.
Which of the following is true about the speed of light?
It depends on the wavelength.
Answer: The wavelength and frequency of light are closely related. The higher the frequency, the shorter the wavelength.
Explanation:
Because all light waves move through a vacuum at the same speed, the number of wave crests passing by a given point in one second depends on the wavelength. That number, also known as the frequency, will be larger for a short-wavelength wave than for a long-wavelength wave.
Answer:
It is a constant when the light is traveling in a vacuum.
Explanation:
NEED ANSWER ASAP According to Ohm’s law, resistance is equal to voltage divided by
current.
conduction.
potential.
time.
Answer:
A
Explanation:
Ohm's law is stated as E = current * resistance (E = I * R)
When you rearrange the formula, you get R = E/I
The answer is current -- A
Answer:
a
Explanation:
Is so2 a formula unit
Answer:
The molecular formula for Sulfur Dioxide is SO2. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Sulfur Dioxide, or 64.0638 grams.
So yes it is a unit
Explanation:
An acid is a substance that donates protons.
true or false please answer asap!!!
Answer:
The correct answer is True.
Explanation:
An acid is a molecule that has the property of donating a proton or accepting a pair of electrons during a reaction.
The strength of an acid is related to their tendency to lose a proton. A strong acid is one that separates all its components when it comes into contact with water.
As its composition includes hydrogen ions, the more its concentration, the higher the acidity will be, and the lower the pH of the solution.
Its main characteristic is that on contact with water they produce a sour taste.
An acid is a substance that donates protons. Therefore, this given statement is very true.
Acid is any material that when dissolved in water has a sour taste, alters the colour of some indicators (blue litmus paper turns red, for example), combines with some metals (like iron) to release hydrogen, reacts chemically bases to produce salts, and catalyses various chemical reactions. Acids are examples of both organic chemicals that belong to the acid group, carboxylic acid, sulfonic acids, or phenol groups as well as the inorganic substances that comprise the mineral acids, such as sulfuric, nitric, hydrochloric, etc phosphoric acids. An acid is a substance that donates protons. Therefore, this given statement is very true.
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12.
Which of these would you expect to be soluble in the nonpolar solvent hexane, C6H14?
A H2O
B. CH,
C Naci
D Sns,
Answer:
B. CH₄
Explanation:
The primary rule in deciding solubilities is, Like dissolves like. That is,
A polar solute dissolves in a polar solvent. A nonpolar solute dissolves in a nonpolar solvent.C₆H₁₄ is a nonpolar solvent. Its strongest intermolecular forces are London dispersion forces.
CH₄ is a nonpolar solute. It contains only nonpolar C-H bonds, and its strongest intermolecular forces are London dispersion forces.
Molecules of the two compounds can easily intermingle with each other because the attractive forces between them are so small.
A is wrong. H₂O is a highly polar substance. Its molecules are so strongly attracted to each other that they will not dissolve in the C₆H₁₄.
C and D are wrong. Both NaCl and SnS are compounds of a metal and a nonmetal. We would predict them to be ionic solids, at the extreme end of polarity. They will not dissolve in C₆H₁₄.
In the nonpolar solvent hexane, CH4 (methane) would be expected to be soluble based on the principle of 'like dissolves like'. Other given substances like H2O, NaCl and SnS2 will not dissolve well in hexane due to their polar ionic and network covalent nature respectively.
Explanation:Among the options given, the substance that would be expected to be soluble in the nonpolar solvent hexane (C6H14) is B. CH4 (methane). This is based on the principle of like dissolves like. Nonpolar solvents, like hexane dissolve nonpolar substances. Methane is a nonpolar substance and will therefore dissolve in hexane. Conversely, H2O (water) and NaCl (table salt) are polar and ionic compounds respectively and SnS2 is a network covalent compound so they will not dissolve well in a nonpolar solvent like hexane.
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The diag
in dilute
Page 6 of 12
A6
A5
(a)
Fluorine, chlorine, bromine and iodine are placed in the same Group of the
Periodic Table.
State the common name used to describe elements in this Group.
(i)
State the Group in which the elements are placed and explain why
they are placed in that Group.
(ii)
Which of the above named elements is a solid at room
temperature and pressure?
Answer:
Here's what I get.
Explanation:
(a) F, Cl, Br, and I are called halogens (salt formers)
(i) They are placed in Group 17, the Group just before Group 18 (the noble gases), because they need just one more valence electron to get a noble gas electron configuration.
(ii) At room temperature, iodine is a lustrous, purple-black solid that melts to form a deep violet liquid at 114 °C.
Match the name of the following compound:
MgSO4 · H2O
Magnesium sulfate monohydrate
Magnesium (II) sulfate monohydrate
Magnesium (II) sulfate hydrate
Magnesium sulfate hydrate
Answer:
number 2 is the answer my friend said
Explanation:
Answer:
Magnesium sulfate monohydrate
Explanation:
The compound is a salt, we have a metal connected to an ion.
To name a salt, first of all, we put the name of the cation, which is the first elemental in the compound. It is followed by the name of the anion.
In this case, the cation is the Magnesium and the anion is the anion sulfate. When the cation can have more than one oxidation number, we need to put this number in parenthesis, like this:
Iron (II) sulfate (FeSO4)
Iron (III) sulfate (Fe2(SO4)3)
However, magnesium can only have 2 as oxidation number, because it's from family 2 in the periodic table. So it's unnecessary to put this information.
As the salt has water in its structure, it's a hydrated salt, and this information needed to be in its name. Because it has only one molecule of water, we put the name monohydrate.
What is the result of multiplying (2.5 × 1010) × (2.0 × 10-7)?
A. 5.0 × 103
B. 5.0 × 10-3
C. 5.0 × 1017
D. 5.0 × 10-17
Answer: The correct option is,
A. [tex]5.0\times 10^3[/tex]
Explanation:
Given expression,
[tex](2.5\times 10^{10})\times (2.0\times 10^{-7})[/tex]
[tex]=2.5\times 2.0\times 10^{10-7}[/tex]
( By using product property of exponent i.e. [tex]a^m\times a^n = a^{m+n}[/tex] )
[tex]=5.0\times 10^3[/tex]
Therefore,
OPTION A is correct.
KMnO4
Assign oxidation numbers to each element in this compound.
K=+1
Mn= +7
O= -2
That’s it!!!
The oxidation number of each element in the compound are:
1. The oxidation number of K is +1
2. The oxidation number of O is –2
3. The oxidation number of Mn is +7
The oxidation number of certain elements are constant while others varies.
The oxidation number of potassium, K is always +1The oxidation number of oxygen, O is always –2 except in peroxides where it is –1Manganese, Mn has variable oxidation number. Thus, we shall determine the oxidation number of Mn in the compoundThe oxidation number of Mn in KMnO₄ can be obtained as follow:
KMnO₄ = 0 (ground state)
K = +1
O = –2
Mn = ?KMnO₄ = 0
K + Mn + 4O = 0
1 + Mn + 4(–2) = 0
1 + Mn – 8 = 0
Collect like terms
Mn = 0 + 8 – 1
Mn = +7Therefore, the oxidation number of Mn in KMnO₄ is +7
SUMMARY
1. The oxidation number of K is +1
2. The oxidation number of O is –2
3. The oxidation number of Mn is +7
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Leslie wants to know which advertising medium works best to promote her electronics store. She surveys her customers over a weekend and creates a bar graph.
Based on her survey, which advertising mediums will work best to publicize Leslie’s in-store specials?
newspaper and printed flyers
radio and TV
radio and Internet
printed flyers and Internet
answer: radio and tv
If a greyhound can run with an average velocity of 60 km/h, how far can it
travel in 30 seconds?
Answer: 0.5 klms
Explanation:
Hope it helped :))
2H2O2 → 2H2O + O2 synthesis decomposition combustion
Answer:
Decomposition
Explanation:
The equation 2 H₂O₂ → 2 H₂O + O₂ is an example of a decomposition reaction. During decomposition, a compound breaks down into two or more products under the favorable conditions, without combining with other reagents.
However, the reaction can be catalyzed using a suitable catalyst.
14. What are the products of the oxidation of glucose?
Answer:
carbon dioxide and water
Explanation:
Answer:
carbon dioxide and water
Explanation:
the molecules represent the products of thorough energy extraction
Having food in the stomach __________ the rate at which a person's BAL rises.
Answer:
Explanation:
It rises Food in your stomach (Food slows down alcohol absorption. What's the best to eat? Protein! It takes the longest to digest)
It will slow down the rate at which a person's BAL rises.
19 grams of sodium and 34 grams of chlorine are measured out and put into separate glass vials that weigh 10 grams each. Then sodium is dumped into the glass vial containing the chlorine. They react and form a crystalline solid. What is the total weight of the glass vial containing the final product?
Answer:
63.02 g.
Explanation:
Na reacts with Cl₂ according to the balanced equation:2Na + Cl₂ → 2NaCl,
It is clear that 2 mole of Na react with 1 mole of Cl₂ to produce 2 moles of NaCl.
Firstly, we need to calculate the no. of moles of Na and Cl₂:no. of moles of Na = (mass/atomic mass) = (19.0 g/22.9897 g/mol) = 0.826 g.
no. of moles of Cl₂ = (mass/atomic mass) = (34.0 g/70.906 g/mol) = 0.48 g.
From the stichiometry, Na reacts with Cl₂ with a molar ratio (2:1).
So, 0.826 mol of Na "the limiting reactant" reacts completely with 0.413 mol of Cl₂ "left over reactant".
The no. of moles of Cl₂ remained after the reaction = 0.48 mol - 0.413 mol = 0.067 mol.
∴ The mass of Cl₂ remained after the reaction = (no. of moles of Cl₂ remained after the reaction)(molar mass of Cl₂) = (0.067 mol)(70.906 g/mol) = 4.75 g.
To get the no. of grams of produced NaCl:using cross multiplication:
2 mol of Na produce → 2 mol of NaCl, from the stichiometry.
∴ 0.826 mol of Na produce → 0.826 mol of NaCl.
∴ The mass of NaCl produced after the reaction = (no. of moles of NaCl)(molar mass of NaCl) = (0.826 mol)(58.44 g/mol) = 48.27 g.
∴ The total weight of the glass vial containing the final product = the weight of the glass vial + the weight of the remaining Cl₂ + the weight of the produced NaCl = 10.0 g + 4.75 g + 48.27 g = 63.02 g.
Answer:
63g
Explanation:
You don't have to make a lot of calculus to find the answer.
Just only remember the principle of the matter who says
"The matter is not created or destroyed only transformed"
It means, that even when you are transforming sodium and chlorine to obtain sodium chlorine, who is the crystalline solid, you can't obtain more matters (grams) that you put at the beginning of the experiment.
As well, you just have to add the grams of the sodium, chlorine and the recipient, glass vial containing the final product, as follow:
19 grams of sodium + 34 grams of chlorine + 10 grams glass vial
19 + 34 + 10 = 29 + 34 = 63 g
remember, the matter isn't create, just transformed, so, you can't add any more grams that you already have.
Think about how you can use Le Chatelier’s principle to find possible solutions to the design problem. Describe at least two ways to increase the yield (amount) of ammonia based on this principle.
Answer:
1) Increasing the pressure.
2) Adding hydrogen gas.
Explanation:
Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.
For the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g):
1) Increasing the pressure:
When there is an increase in pressure, the equilibrium will shift towards the side with fewer moles of gas of the reaction. And when there is a decrease in pressure, the equilibrium will shift towards the side with more moles of gas of the reaction.The reactants side (left) has 4.0 moles of gases and the products side (right) has 2.0 moles of gases.So, increasing the pressure will shift the reaction to the side with lower moles of gas (right side) that increase the yield (amount) of ammonia.
2) Adding hydrogen gas:
Adding hydrogen gas will increase the concentration of the reactants side, so the reaction will be shifted to the right side to suppress the increase in the concentration of hydrogen gas by addition that increase the yield (amount) of ammonia.Answer:
The La Chatelier's principle suggests that changes in the products of the design, we can increase the pressure of the equilibrium when we do this it will shift towards the side with fewer moles of gas of the reaction, and when there is a decrease in pressure, the equilibrium will shift towards the side with more moles of gas of the reaction.
Then we can also add hydrogen gas, by doing this it will increase the concentration of the reactants side, so the reaction will be shifted to the right side to suppress the increase in the concentration of hydrogen gas by addition that increase the yield of ammonia.
Explanation:
Identify which properties could correspond to solids, plasmas, or both.
maintain a unique shape.
____particles collide infrequently with other particles.
____particles have very high velocities.
____can conduct electricity.
____contain protons.
____typically have a low temperature.
____structure has long-range order.
Explanation:
Plasma is defined as the state of matter which is a hot ionized gas that consists of positively charged ions and negatively charged electrons.
Like gases, particles of a plasma are also held by weak forces that are Vander waal forces. And, as it is a hot ionized gas therefore, particles of plasma move rapidly from one place to another.
In a solid, molecules are held together by strong intermolecular forces of attraction. As a result, they are unable to move from their initial place but they can vibrate at their mean position.
Hence, in solid substances the molecules have low kinetic energy. Also, molecules in a solid are placed in a long range order.
Solids like copper, silver etc able to conduct electricity.
Also, both plasma and solids contain proton because every atom contains neutrons, protons and electrons.
Thus, we identify the properties corresponding to solids, plasmas, or both are as follows.
Solids maintain a unique shape.Plasma particles collide infrequently with other particles.Plasma particles have very high velocities.Both can conduct electricity.Both contain protons.Solids typically have a low temperature.Solids structure has long-range order.Answer:
Identify which properties could correspond to solids, plasmas, or both.
Solids
maintain a unique shape.
Plasma
particles collide infrequently with other particles.
Plasma
particles have very high velocities.
Both solids and plasmas
can conduct electricity.
Both solids and plasmas
contain protons.
Solids
typically have a low temperature.
Solid
structure has long-range order.
Explanation: