Answer: the answer is Z
Which compounds are used in mineral-based sunscreens?
The correct answer is A. The compounds used in mineral-based sunscreens are zinc oxide (ZnO) and titanium dioxide (TiO₂).
The compounds used in mineral-based sunscreens are Zinc oxide (ZnO) and Titanium dioxide (TiO₂). Zinc oxide and titanium dioxide are effective at protecting from the sun. These compounds effectively protect the skin by reflecting, scattering, and absorbing UV radiation.
They work by sitting on top of the skin and reflecting, scattering, and absorbing ultraviolet (UV) radiation rather than allowing it to penetrate the skin.
Complete Question:
Which compounds are used in mineral-based sunscreens?
a. ZnO and TiO₂
b. ZnO and CdS
c. TiO₂ and SiO₂
d. CdS and SiO₂
What is the name of the compound cs (mno4)2
a. Cadmium manganate
B. Cadmium manganate
C. Cadmium manganate
D. Cadmium permangantie
The name of the compound Cs(MnO4)2 is Cesium Permanganate.
Explanation:The compound Cs(MnO4)2 is correctly named as Cesium Permanganate. In this compound, Cs represents the element Cesium and MnO4 represents the polyatomic ion called Permanganate. The suffix -ate typically denotes ions that include oxygen
The compound Cs(MnO4)2 is called cesium permanganate.
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How can you determine if elements have similar chemical properties?
The similarity of chemical properties in elements can be determined by their position in the periodic table, specifically in the same group or period.
Similar chemical properties in elements can be determined by looking at their position in the periodic table and their electronic configurations.
Elements in the same group or column of the periodic table have similar chemical properties because they have the same number of valence electrons, which are responsible for bonding and chemical reactions. For example, all elements in Group 1 (alkali metals) have similar properties, such as being highly reactive and easily forming positive ions.
Additionally, elements in the same period or row of the periodic table have similar chemical properties because they have the same number of electron shells. For example, elements in Period 3 all have three electron shells, which influences their reactivity and bonding behavior.
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why didn't mendeleev include helium , neon and argon in his periodic table?
Answer choices are:
A. These elements did not fit in with his pattern.
B. These elements are gases and he didn't include gases.
C. The atoms of these elements had no atomic mass.
D. These elements had not yet been discovered.
___________________________________________________________
Correct answer choice is:
D. These elements had not yet been discovered.
____________________________________________________________
Explanation:
Mendeleev would have no precise logic to presume there were lacking elements when they can be distributed by various units. But he did note bearings and was capable to divine some holes based on these bearings. The whole column of noble gases, though, could be dropped as it was a periodic recess, not a recess in the period.
Mendeleev added the noble gases later, near the edge of his life, during enough proof was received.
Calculate the standard entropy change for the dimerization of no2: 2 no2(g) → n2o4(g) at 298 k, if s ◦ ∆h◦ f j k·mol kj mol no2(g) 240.06 33.18 n2o4(g) 304.29 9.16 answer in units of j k · mol
The standard entropy change for the dimerization of NO2 at a temperature of 298 K is calculated to be -175.83 J/K·mol.
Explanation:The probability of Type I error is denoted by alpha (α), and in hypothesis testing, we typically set a predetermined level of significance (α), which is the maximum allowable probability of making a Type I error.This incorrect rejection is often influenced by the level of significance used in the test. The likelihood of a Type I error occurring is often denoted by the Greek letter alpha, α. The lower the value of α, the less likely you are to make a Type I error.The standard entropy change for the dimerization of NO2 can be calculated using the equation: ΔS° = ΣS°(products) - ΣS°(reactants). The standard entropy (ΔS°) values for the reactants and products are given as follows: for NO2(g), S° = 240.06 J/K·mol; and for N2O4(g), S° = 304.29 J/K·mol. Therefore, the standard entropy change for the dimerization of NO2 at 298 K becomes:ΔS° = [1 x S°(N2O4)] - [2 x S°(NO2)] = [1 x 304.29 J/K·mol] - [2 x 240.06 J/K·mol] = -175.83 J/K·mol. The probability of Type I error is denoted by alpha (α), and in hypothesis testing, we typically set a predetermined level of significance (α), which is the maximum allowable probability of making a Type I error.This incorrect rejection is often influenced by the level of significance used in the test. The likelihood of a Type I error occurring is often denoted by the Greek letter alpha, α. The lower the value of α, the less likely you are to make a Type I error.
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How many moles of water are produced when 3.45 moles of KMnO4 react? Give your answer to the nearest 0.1 moles
Final answer:
The number of moles of water produced when 3.45 moles of KMnO₄react is 5.2 moles.
Explanation:
To determine the number of moles of water produced when 3.45 moles of KMnO₄ react, we need to look at the balanced chemical equation for the reaction. Let's assume the reaction is balanced as follows:
2 KMnO₄ + 3 H₂O -> 2 MnO₂+ 2 KOH + 3 O₂
From the balanced equation, we can see that 3 moles of water are produced for every 2 moles of KMnO₄ reacted. Therefore, if 3.45 moles of KMnO4 react, we can calculate the number of moles of water produced using a proportion:
(3.45 moles KMnO₄) x (3 moles H₂O / 2 moles KMnO₄) = 5.175 moles H₂O
Rounding it to the nearest 0.1 moles, the number of moles of water produced is 5.2 moles.
When 3.45 moles of KMnO4 react, approximately 6.9 moles of water are produced. Rounding to the nearest 0.1 mole, the answer is 6.9 mol.
To find the moles of water produced, we need to follow these steps:
1. **Balance the chemical equation:** The balanced equation for the reaction of KMnO4 with water is:
2KMnO4 + 8H+ -> 2Mn2+ + K2SO4 + 4H2O
2. **Use the stoichiometric coefficients:** From the balanced equation, we see that for every 2 moles of KMnO4 that react, 4 moles of water are produced.
3. **Calculate the moles of water:**
- Moles of water produced = (Moles of KMnO4 reacted) * (Moles of water produced per mole of KMnO4)
- Moles of water produced = (3.45 mol) * (4 mol H2O / 2 mol KMnO4)
- Moles of water produced = 6.9 mol
Therefore, when 3.45 moles of KMnO4 react, approximately 6.9 moles of water are produced. Rounding to the nearest 0.1 mole, the answer is 6.9 mol.
What intermolecular forces occur between two methane molecules?
Which of the following statements about asteroids is true?
A.
Asteroids vary greatly in size and are mostly made up of frozen water and gas.
B.
Asteroids vary greatly in size and are mostly made up of stone, iron and nickel.
C.
Asteroids are all very large and are mostly made up of stone, iron and nickel.
D.
Asteroids are all very large and are mostly made up of frozen water and gas.
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What is the range of the numbers of isotopes chemical elements have?
The range of the number of isotopes that chemical elements can have is b
. 3 to 36.
The element with the least (3) number of isotopes is Hydrogen, while the elements with the most number (36) of possible isotopes are Xenon and Cesium.
Isotopes are different forms of the same element, in which the number of protons in the nucleus of the atom is the same for the different forms, but the number of neutrons in the nucleus is different. Isotopes are atoms with the same number of protons but different numbers of neutrons. The range of isotopes for chemical elements varies, with some elements having multiple isotopes. Isotope stability can vary among different isotopes of an element.Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons, leading to different mass numbers. The range of isotopes for chemical elements can vary significantly. For instance, thallium has 25 isotopes with atomic masses ranging from 184 to 210.The stability of isotopes differs, with some being more stable than others.
Correct question is: What is the range of the numbers of isotopes chemical elements have?
a. 4 to 45
b. 3 to 36
c. 2 to 34
d. 5 to 12
For which atom is it difficult to predict the most probable ionic charge using the periodic table?
The atom for which the prediction of ionic charge has been difficult based on the periodic table is Cobalt.
The ionic charge has been imposed on the atom when there has been a loss or gain of an electron, in order to achieve the stable electronic configuration. The elements on the loss of electron have attained a +ve charge, while the gain of an electron by an atom gives it a -ve charge.
The elements in the periodic table have an oxidation state for the ionic form of the elements. The varying oxidation state element has been able to attain a varying ionic state. Cobalt has been present with varying oxidation states, thus it has been difficult to predict the ionic charge of Cobalt using the periodic table.
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How could you turn a heterogeneous mixture of salt,sugar, and baking soda into a homogeneous mixture?
By dissolving all the mixture in water and mixing it thoroughly.
How do you shape a homogeneous mixture of sugar and salt?A homogeneous aggregate is a form of combination in which the composition is uniform and each part of the solution has the same properties. Salt, sugar, and many different materials dissolve in water to shape homogeneous combinations.
How do you make a heterogeneous mixture?A phase is any part of a pattern that has a uniform composition and properties. By definition, a pure substance or a homogeneous combination includes a single phase. A heterogeneous mixture consists of more phases. whilst oil and water are mixed, they do not blend lightly, however as an alternative form two separate layers.
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How many grams of sodium iodide, nai, must be used to produce 97.1 g of iodine, i2?
What does ph measure? the concentration of oxygen atoms in solution the total number of acid molecules in solution the concentration of hydrogen ions in solution the total number of base molecules in solution brainly?
Answer:
the concentration of hydrogen ions in solution
Explanation:
pH stands for potenz of hydrogen.
pH is measure of hydrogen ion concentration.
pH is calculated as :
pH = -log[H⁺]
where [H⁺] is concentration of hydrogen ions.
Thus pH is measure of hydrogen ions concentration.
the other statements are wrong
i) total concentration of oxygen is not related to pH measure.
ii) total number of acid molecules is also not direct measure of pH.
iii) total number of base molecules cannot be measure of pH.
Identify the subshell corresponding to the lowest energy peak in the photoelectron spectrum (pes) of sulfur.
Barium ions carry a 2+ charge, and nitrogen ions carry a 3-charge. what would be the chemical formula for the ionic compound barium nitride?
In which group do all atoms have seven valence electrons in the ground state?
Group 7A or the 17th column on the periodic table, known as the halogens, contains elements with seven valence electrons. Their electron configuration is ns²np5.
The group in which all atoms have seven valence electrons in the ground state is the halogen group, also known as Group 7A or the 17th column of the periodic table. These elements have the valence shell electron configuration of ns²np5, where n represents the principal quantum number corresponding to the period number of the element in the periodic table. For example, chlorine (Cl) has the electron configuration [Ne] 3s² 3p5, indicating that it has seven valence electrons. This is because the p subshell is being filled with five electrons alongside the two electrons in the s subshell, summing up to seven valence electrons.
Toy balloons are filled with hydrogen gas, at standard temperature, from a 10.0-liter cylinder. the initial pressure of the gas in the cylinder is exactly 100 atm. assuming each balloon is filled to a volume of 1.0 liter at standard pressure, how many balloons could be filled?
What is material that will sink in Liquid water @ 4c
A. Aluminum
B. Corn oil
C. Ice
D gasoline
Parts of Dalton’s atomic theory were disproved. Do you think that this should be taken as a criticism of Dalton as a scientist? Use a description of what you think a good scientist is to support your answer
Which of the following depends on an object's displacement not distance from the starting point?
Question 2 options:
Velocity
Acceleration
Displacement
Speed
Answer: The velocity of an object depends on an object's displacement.
Explanation:
Velocity is defined as displacement of an object with respect to time.
It is a vector quantity measured in meter per second or m/s.
Mathematically
[tex]v=\frac{displacement}{\text{time taken}}[/tex] or [tex]v=\frac{dx}{dt}[/tex]
AB + C → AC + B is the general equation for which one of the following types of chemical reactions?
Lab worksheets oh what a tangled web we weave
Questions:
1. In how many food chains do the following animals appear? (count the # of food chains in part B)
hawk ___4__ earthworm ___2__ fox __6___
owl ___3__ snake __4___ small insects__1__
2. In how many food chains do plants (parts) appear? __all(14)__
3. List the names of the living things in this forest ecosystem that are producers. Plant parts
4. List those things that are only primary consumers. Crickets, earthworms, small insects, land snails, rabbits, and sparrows.
5. What is another name for an animal that is only a primary consumer? Herbivore
6. List those things that are only secondary consumers. Foxes, Hawks, Owls, Robins, Snakes.
7. What is another name for an animal that is only a secondary consumer? Carnivore
8. List the consumers that eat both plants and animals. Mouse, raccoon
9. What is another name for an animal that eats both plants and animals? Omnivore
10. What would happen to the food web if all the plants were removed? Everything will die. Explain your answer. Plants are the only organisms that can make their own food.
11. Describe how 3 animals might be affected if owls were removed from the food chain. Rabbits, mice, and snakes will probably increase since one of their predators is gone.
12. Draw three food chains showing producers and consumers that you might see in your backyard or on your way to school. (You may use words or drawings.)
grass → grasshopper → robin
nut → squirrel → cat
berry → bird → cat
(OR ANY OTHER VALID EXAMPLE)
13. Since only 10% of the energy produced by a level in a food chain is passed on to its predator, there have to be many more “prey” than “predators”. Draw a food pyramid of the first food chain listed in Part A. Remember that there are more producers than primary consumers, more primary consumers, and secondary consumers, etc.
raccoon
mouse
land snail
plant parts
14. If 2000 kcal of energy are available in the grass, how much energy would be available to the cow that eats the grass? To the human that eats the cow?
Assuming that all energy is used:
Since only 10% of the energy is available to the next level consumer – (.1)(2000 kcal) = 200 kcal of energy available to the cow. For the human (.1)(200 kcal) = 20 kcal available to the human. In other words, the human-only receives 1% of the original energy produced by the plant.
15. Which organism in this food web has the greatest influence on the ecosystem? Justify your answer.
This is a really tough one to answer. In reality, they are all equally important, and time should be spent going over all possibilities. Most students will guess plants since all life depends on the energy produced by plants. The teacher should also point out that, if a top-level consumer is killed off, the organisms it eats will increase in population, which might mean that more grass will be eaten, etc. All attempts should be made to show the interdependence of organisms in an ecosystem and to show that they are, therefore, all important.
Food web and Livings Things the Forest Eat graph
When calcium (ca) bonds with oxygen, it gives up two electrons. what is the charge of the ca ion in this compound?
Explanation:
Atomic number of calcium is 20 and its electronic distribution is 2, 8, 8, 2. Hence, to attain stability it will readily lose its valence electrons.
Hence, neutral Ca atom will change into [tex]Ca^{2+}[/tex] ion.
Whereas atomic number of oxygen is 8 and its electronic distribution is 2, 6. Hence, to attain stability it will needs to gain two electrons.
Hence, neutral O atom will change into [tex]O^{2-}[/tex] ion.
Therefore, when both calcium and oxygen atoms will chemically combine with each other then according to cross multiplication same charges will be cancelled out resulting in the formation of calcium oxide (CaO) compound.
Thus, we can conclude that charge on calcium in this compound is +2.
Which of the following is not true of a pseudoscience? (1 point) It does not follow the scientific method. It is not proven reliable through experimentation. It is a practice or belief that claims to be science. It is a science that is controversial or unproven.
Answer: It is a science that is controversial or unproven.
Explanation:
Pseudoscience can be based upon the belief, statements or practices that are claimed to be factual as well as scientific but actually not. As it is not proved by the scientific experimental procedures. Hence, it cannot be considered as scientific but can become controversial and unproven as it lack evidences.
A radioactive substance decays exponentially. a scientist begins with 190 milligrams of a radioactive substance. after 17 hours, 95 mg of the substance remains. how many milligrams will remain after 21 hours
To calculate how many milligrams will remain after 21 hours, we can use the formula for exponential decay. We are given that after 17 hours, 95 mg of the substance remains. Solving for the remaining amount after 21 hours gives us approximately 88.66 mg.
Explanation:To calculate how many milligrams will remain after 21 hours, we can use the formula for exponential decay:
R = Ro * e^(-kt)
Where:
R is the remaining amount after time tRo is the initial amountk is the decay constantt is the time periodWe are given that after 17 hours, 95 mg of the substance remains. Plugging these values into the formula, we can solve for k:
95 = 190 * e^(-17k)
Simplifying, we get:
e^(-17k) = 1/2
Taking the natural logarithm (ln) of both sides:
-17k = ln(1/2)
Solving for k, we find k = ln(1/2) / -17.
Now, we can use this value of k to find the remaining amount after 21 hours:
R = 190 * e^(-kt)
R = 190 * e^(-(ln(1/2) / -17) * 21)
Calculating this expression will give us the remaining amount after 21 hours, which is approximately 88.66 mg.
Chanice drives her scooter 7 kilometers north she stops for lunch and then drives 5 kilometers east what distance did she cover?? What was her displacement
Answer:
Total distance of covered by Chanice is 12 km
8.60 km was her displacement in the direction of north-east.
Explanation:
Distance covered by Chanice in north direction = 7 km
Distance covered by Chanice in an east direction = 5 km
Total distance of covered by Chanice = 7 km+ 5 km = 12 km
Displacement is defined as shortest distance from initial point to final point.
In a ΔABC, the displacement of the Chanice = AC
ΔABC, is a right angled triangle.So, by applying Pythagoras theorem we can determine the the length of AC.
[tex]AB^2+BC^2=AC^2[/tex]
[tex](7 km)^2+(5 km)^2=AC^2[/tex]
AC = 8.60 km
8.60 km was her displacement in the direction of north-east.
Final answer:
The distance Chanice covered on her scooter is the sum of her northward and eastward travels, 12 km. Her displacement is the hypotenuse of the right triangle formed by her path, approximately 8.6 km. The magnitude of her displacement is also about 8.6 km.
Explanation:
Chanice drives her scooter 7 kilometers north and then 5 kilometers east. The distance she covered is the total length of her travel path, which is the sum of these two separate distances.
The displacement, however, is the shortest path between her starting and ending points, measured in a straight line. In Chanice's case, we can calculate this by envisioning a right triangle where the legs of the triangle are her northward and eastward paths. The hypotenuse of this triangle will be her displacement. Using the Pythagorean theorem, displacement (Δd) can be calculated as Δd = √(7² + 5²) = √(49 + 25) = √74, which is approximately 8.6 kilometers.
The magnitude of her displacement is the absolute value of her displacement, which is simply the hypotenuse calculated above, about 8.6 kilometers.
How to determine is an alcohol has strong or weak intermolecular forces?
according to Le chateliers principle when a change is introduced into a system in chemical equilibrium the equilibrium shifts.
A) to the forward reaction.
B) to the reverse reaction
C) In the direction that relieves the change
D) in the direction that requires the most energy
An ionic bond is a bond between _____. a cation and an anion the ions of two different nonmetals valence electrons and cations the ions of two different metals
Answer: An ionic bond is a bond between a cation and an anion.
Explanation:
You can find the definition of ionic bond as the electrostatic force that bonds together the cations and anions in a ionic compound.
Cations are positively charged particles formed by the lack (loss) of electrons of the atoms.
Anions are negatively charged particles formed by the excess (gain) of electons of the atoms.
Therefore, being anions and cations particles with opposed charges, they will be attracted to each other by electrostatic force.
This electrostatic force that bonds together the cations and anions (particles with opposed charges) is named ionic bond.
The ionic bonds are typical of the cations formed by the metals, especially alkalyne metals (group 1 elements) and alkalyne earth metals (group 2 elements), with the anions formed by the non-metals, for instance oxygen (group 16) and halogens (group 17). The relative high difference in the electronegativities of these metals and non-metals permit that the metals transfer some few electrons to the non-metals, forming the respective cations and anions, which will result in the ionic bond between them.
The process of removing an electron from a stable nucleus is known as