What parts of Dalton’s atomic theory no longer agree with the current picture of the atom? Provide an answer using 3 – 4 sentences in your own words.
A thermometer is placed in water in order to measure the water’s temperature. What would cause the liquid in the thermometer to rise?
The molecules in the water move closer together.
The molecules in the thermometer’s liquid spread apart.
The kinetic energy of the water molecules decreases.
The kinetic energy of the thermometer’s liquid molecules decreases
Answer: Option (b) is the correct answer.
Explanation:
When we use a thermometer to measure the temperature of water then heat from the water will lead to represent an increase in the thermometer reading.
This is because heat or warmth from the water will get transferred to the thermometer as a result, the liquid in the thermometer will also get warm.
Therefore, this warmth will increase kinetic energy of the molecules of liquid in the thermometer. Hence, the liquid will spread.
Thus, we can conclude that the liquid in the thermometer to rise because molecules in the thermometer’s liquid spread apart.
The chemical properties of calcium most similairto the chemical properties of
What is the mass of 2 moles of 238 u?
Answer:
Mass of 2 moles of [tex]^{238}\textrm{U}[/tex] is 476.1 g
Explanation:
We know that number of moles of an atom is ratio of mass of the atom to it's atomic weight.Atomic weight of [tex]^{238}\textrm{U}[/tex] is 238.05 g/molSo, mass of 1 mol of [tex]^{238}\textrm{U}[/tex] atom is 238.05 gHence mass of 2 moles of [tex]^{238}\textrm{U}[/tex] = [tex](2mol\times 238.05g/mol)=476.1 g[/tex]Hence mass of 2 moles of [tex]^{238}\textrm{U}[/tex] is 476.1 gIn a coffee shop, the following coffee samples are prepared for customers. i. 10 g of sugar added to 100 g of coffee ii. 10 g of sugar added to 200 g of coffee iii. 4 g of sugar added to 200 g of coffee iv. 4 g of sugar added to 100 g of coffee Based on the amount of sugar added, which sequence ranks the coffee from the sweetest coffee to the least-sweet coffee?
The sequence that ranked the coffee from the sweetest coffee to the least-sweet coffee is: i, ii, iv, iii
To obtain the correct answer to the question, we shall determine the percentage of sugar in each solution. This is illustrated below:
i. How to determine the percentage of the sugarMass of sugar = 10 gMass of coffee = 100 gPercentage of sugar =?Percentage = (mass of solute / mass of solution) × 100
Percentage of sugar = (10 / 100) × 100
Percentage of sugar = 10%
ii. How to determine the percentage of the sugarMass of sugar = 10 giiMass of coffee = 200 gPercentage of sugar =?Percentage = (mass of solute / mass of solution) × 100
Percentage of sugar = (10 / 200) × 100
Percentage of sugar = 5%
iii. How to determine the percentage of the sugarMass of sugar = 4 gMass of coffee = 200 gPercentage of sugar =?Percentage = (mass of solute / mass of solution) × 100
Percentage of sugar = (4 / 200) × 100
Percentage of sugar = 2%
iv. How to determine the percentage of the sugarMass of sugar = 4 gMass of coffee = 100 gPercentage of sugar =?Percentage = (mass of solute / mass of solution) × 100
Percentage of sugar = (4 / 100) × 100
Percentage of sugar = 4%
Thus, the sequce from sweetest coffee to the least sweet coffee is i, ii, iv, iii
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Final answer:
The sweetness of the coffee depends on the amount of sugar added, with more sugar making it sweeter. The sequence from sweetest to least sweet is: 10 g of sugar added to 200 g of coffee, 10 g of sugar added to 100 g of coffee, 4 g of sugar added to 200 g of coffee, 4 g of sugar added to 100 g of coffee.
Explanation:
The sweetness of the coffee can be determined by the amount of sugar added to it. Comparing the sequences, we can see that the coffee with the largest amount of sugar added will be the sweetest, and the coffee with the least amount of sugar added will be the least sweet. So, the sequence that ranks the coffee from the sweetest to the least sweet is:
10 g of sugar added to 200 g of coffee
10 g of sugar added to 100 g of coffee
4 g of sugar added to 200 g of coffee
4 g of sugar added to 100 g of coffee
75.0 moles of argon gas at stp
The volume of 75.0 moles of argon gas at STP is 1680 liters, calculated by multiplying the number of moles by the molar volume of 22.4 L/mole.
The question pertains to the properties of argon gas under different conditions, specifically its behavior at standard temperature and pressure (STP), and how its volume can be calculated using the ideal gas law.
At STP, one mole of any gas occupies 22.4 L. Therefore, for 75.0 moles of argon, the volume can be calculated by multiplying the number of moles by the molar volume at STP.
Volume
= moles ×molar volume at STP
= 75.0 moles × 22.4 L/mol
= 1680 L
I'm kinda in a rush but take your time!Thx! 1.What was Henri Becquerel studying when he accidentally discovered radioactivity?
A.photography B.properties of black light C.properties of X-rays D.solar energy 2.When Marie Curie isolated uranium from pitchblende, she realized that the pitchblende was more radioactive than the uranium she had extracted. What did she conclude about her observations?
A.Pitchblende itself is a radioactive element B.The pitchblende sample contained an unknown radioactive element
C.The pitchblende sample was defective D.Pitchblende should be used as radiation therapy 3.Henri Becquerel's original hypothesis was that fluorescent minerals became excited by a solar energy and gave off X-rays. However, after he discovered uranium minerals emitted their own radiation without the help of solar energy, he abandoned his hypothesis. Why did Becquerel abandon his first hypothesis?
A.He was afraid of ridicule from the scientific community for being wrong
B.He found new evidence that didn't support his original hypothesis
C.He couldn't repeat the results in multiple experiments.
D.He couldn't make the experiment work, so he came up with a new plan
4.Marie Curie had many "firsts". Which of the following is not one of Marie Curie's firsts?
A.first female Nobel Prize winner B.first female professor in the Faculty of Sciences
C.first to suggest that atoms can change D.first to discover X-rays My answers: 1.D 2.B 3.A 4.D
Henri Becquerel was studying the properties of X-rays when he discovered radioactivity. Marie Curie concluded that pitchblende must contain another, more radioactive element upon finding it was more radioactive than its uranium content. Curie was not the first to discover X-rays; that was Roentgen.
Henri Becquerel was studying the properties of X-rays when he accidentally discovered radioactivity. He was experimenting with phosphorescent materials and their ability to produce X-rays after being exposed to sunlight when he observed that uranium salts emitted rays without the need for sunlight, leading to the discovery of radioactivity.
Upon isolating uranium from pitchblende and finding that the pitchblende was more radioactive than the purified uranium, Marie Curie concluded that the pitchblende contained unknown radioactive elements. This led to the discovery of two new elements, polonium, and radium, which were significantly more radioactive than uranium.
Becquerel abandoned his first hypothesis, which postulated that fluorescent minerals excited by solar energy emitted X-rays because he found evidence that uranium emits radiation regardless of exposure to sunlight, thus invalidating his original theory. He adapted his hypothesis based on the evidence he collected that showed uranium's radiation was not dependent on light or fluorescence.
Marie Curie had many firsts in her career, but she was not the first to discover X-rays. That discovery was made by Wilhelm Roentgen in 1895. Marie Curie's notable firsts include being the first female Nobel Prize winner, the first female professor at the Faculty of Sciences at the Sorbonne, and the first person to coin the term radioactivity and suggest that atoms could change as part of radioactive decay.
What volume would 3.01•1023 molecules of oxygen gas occupy at STP?
the answer is c) 11.2 L
edge 2021
Is the following equation balanced? 2Na + 2H2O = 2NaOH + H2
Yes
No
Answer:
Yes
Explanation:
2Na + 2H2O → 2NaOH + H2
A chemical equation is balanced if the number of atom of elements on the reactant side is equal to the number of atom of elements on the product sides.
According to the equation above the chemical equation is balanced .From the equation 2 moles of sodium reacted with 2 moles of water to form 2 moles of sodium hydroxide and hydrogen gas.
On the reactant side(left side), the sodium has 2 atom of sodium and the water molecule has 4 atom of hydrogen and 2 atom of oxygen.
On the product side(product side), the sodium hydroxide compound have 2 atom of sodium , 2 atoms of oxygen and 2 atoms of hydrogen . The hydrogen gas has 2 atoms of hydrogen. Adding the hydrogen atom on the product side will give you 4 atoms of hydrogen.
From the illustration above you could notice the equation is balanced.
How many grams of O2 are in 5.0 moles of the oxygen gas?
Answer : The mass of oxygen is 160 grams.
Solution : Given,
Moles of [tex]O_2[/tex] = 5 moles
Molar mass of [tex]O_2[/tex] = 32 g/mole
Formula used :
[tex]\text{ Mass of }O_2=\text{ Moles of }O_2\times \text{ Molar mass of }O_2[/tex]
[tex]\text{ Mass of }O_2=(5moles)\times (32g/mole)[/tex]
[tex]\text{ Mass of }O_2=160g[/tex]
Therefore, 160 grams of [tex]O_2[/tex] are in 5.0 moles of the oxygen gas.
When nitrogen and magnesium form an ionic bond, what is the formula?
N3Mg2
N2Mg3
Mg2N3
Mg3N2
#1: 2H2O + 2K (s) 2KOH (l) + 2H2 (g) is an example of which type of reaction?
A. single-displacement
B. combustion
C. decomposition
D. double-displacement
Answer:
D) double-displacement
Explanation:
In a displacement reaction, one or more atoms replace one or more atoms of a given molecule to form a new one.
In this case, two atoms of K replace two atoms of H in the water molecules two form H2 and KOH.
Is double because two displacement happen in the global reaction equation.
write the mole ratio of (Mg+2HF➡MgF+H2)
Answer:
Mg+2HF>2MgF+H2
Explanation:
What is the distance from one crest to the next crest is the??
Answer:
wavelength
Explanation:
The distance from one crest to the next crest is called the wavelength.
A magnet is an example of a
contact force
distance force
gravitational force
electrical force
How does the solubility of a gas change with increasing temperature??
Household hazardous waste can be eliminated by preparing your own cleaning products using the following ingredients EXCEPT: vinegar bicarbonate soda cornstarch Windex
I think the correct answer from the choices listed above is the last option. Household hazardous waste can be eliminated by preparing your own cleaning products using the following ingredients except Windex.
It is a chemical product that is hazardous.
Explanation:
Windex may be a glass and hard-surface cleaner. Windex was unreal by the Drackett Company in 1933 and has been marketed throughout.Windex cannot be used.
Windex is the ingredient that should not be used for preparing non-toxic, homemade cleaning products. Vinegar, baking soda, and cornstarch are all safe alternatives that can effectively clean and reduce household hazardous waste when used in homemade cleaning solutions.
The student's question pertains to the elimination of household hazardous waste by preparing one's own cleaning products. Among the ingredients listed, vinegar, bicarbonate soda (baking soda), and cornstarch are common safe household ingredients used for cleaning purposes. However, Windex is a commercial product which often contains chemicals and is not a suitable ingredient for making your own non-toxic, homemade cleaning products.
Homemade cleaning solutions, such as a mixture of vinegar and baking soda, can serve as effective alternatives to reduce the presence of hazardous substances in the household. These natural products are not only eco-friendly, but also pose less risk to personal health compared to some commercially available cleaners.
what type of reaction occurs between aqueous ammonia solution and an acid?
need it before tomorrow.
Answer:
Neutralization reaction occurs between aqueous ammonia solution and an acid.
Explanation:
Reaction that takes place between aqueous ammonia and acid is neutralization reaction.
A neutralization reaction is defined as chemical reaction between acid and base which results in formation of salt and water as a product.
[tex]NH_3(g)+H_2O(l)\rightarrow NH_4OH(aq)[/tex]
So, when HCl reacts with liquid ammonia it gives aqueous solution of ammonium chloride and water as a predict.
[tex]NH_4OH(aq)+HCl(aq)\rightarrow NH_4Cl(aq)+H_2O(l)[/tex]
Determine the empirical formula for a compound that is found to contain 10.15 mg P and 34.85 mg Cl.?
But I'm confused because I thought I had to convert 10.15 mg to grams but then I get a huge number if I do that. Why do I leave it as mg?
Final answer:
To determine the empirical formula for a compound containing phosphorus and chlorine, convert mass to grams, calculate moles using molar mass, then find the whole-number ratio of elements. The empirical formula is PCl3.
Explanation:
To determine the empirical formula for a compound containing phosphorus (P) and chlorine (Cl), we first need to convert the mass of each element from milligrams to grams for consistency with molar mass units. The mass of P is 10.15 mg, which equates to 0.01015 g, and the mass of Cl is 34.85 mg, which is 0.03485 g.
Next, we use the molar mass of each element (P: 30.97 g/mol, Cl: 35.45 g/mol) to convert the mass of each element to moles. For P, 0.01015 g × (1 mol / 30.97 g) = 0.0003277 mol. For Cl, 0.03485 g × (1 mol / 35.45 g) = 0.0009830 mol.
To find the whole-number ratio, we divide the moles of each element by the smallest number of moles obtained from the calculation:
P: 0.0003277 / 0.0003277 = 1Cl: 0.0009830 / 0.0003277 ≈ 3Therefore, the empirical formula for the compound is P1Cl3.
Define element and compound. explain the difference between an element and a compound.
Answer:
Element is a pure substance which cannot be splitted into smaller substances by simple chemical reactions. while Compound is a chemical combination of two or more substances at fixed ratio.
For which element are the number of protons, electron, and neutrons are 36, 36, and 48 respectively? a cadmium b rubidium c bromine d krypton
Atoms of different elements cannot have the same atomic number since only atoms of the same kind unite to produce an element. Atoms from different elements may have distinct atomic numbers. Therefore, the correct option is option d.
What is element?Element is made up of atoms or atoms together to make element. Atoms of a given element are always the same, which means that all of the properties among all atoms within one kind of element are the same.
Two or more atoms with dissimilar physical or chemical characteristics cannot unite to form an element. For Krypton element, the number of protons, electron, and neutrons are 36, 36, and 48 respectively.
Therefore, for Krypton element, the number of protons, electron, and neutrons are 36, 36, and 48 respectively. the correct option is option d.
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Choose one property of water that makes it unique describe the property and explain the chemical or physical reasons that causes water to have to property.
Water has high heat specific capacity. Heat specific capacity is the amount of heat that is needed to raise the temperature of one gram of particular substance by one degree Celsius. The high specific heat capacity of water is due to the hydrogen bond that exist among the molecules of water. The hydrogen bond is quite strong and it will take a lot of heat to break the bonds. Thus, it takes a lot of heating to increased the temperature of water by one degree Celsius. This is also the reason why water has high boiling point.
The official web site of the Nobel Prize explains that Marie Curie’s chemistry prize was partly for her discovery that the radioactivity of a substance is unaffected when it undergoes a chemical reaction. What does this discovery imply?
A.Radioactivity involves all particles that make up an atom.
B.Radioactivity involves the particles that make up an atom’s nucleus.
C.Radioactivity involves only neutrons.
D.Radioactivity involves only the electrons in an atom’s electron cloud.
Answer:
The answer is A on edg hope that helps
in general what happens when you increase the temperature of a reaction
In general, atoms react in an attempt to attain the electron configuration of a noble gas.
a. true
b. false
4Fe+3O2
I really have no idea how to do this.. HELP
What changes in the nucleus during nuclear decay by gamma rays A Energy content B Atomic MASS C Atomic number D All of the above.
Final answer:
The correct answer is "atomic mass & atomic number". During nuclear decay by gamma rays, only the energy content of the nucleus changes; atomic mass and atomic number remain constant.
Explanation:
In the process of nuclear decay by gamma rays, there is no change in the atomic mass or atomic number of the nucleus. The only change that occurs during gamma decay is in the energy content of the nucleus. During gamma decay, a nucleus in an excited state drops to a lower energy state by emitting high-energy photons known as gamma rays. This is often represented by the metastable state, labeled with an 'm' next to the mass number. Despite this change in energy, the number of protons (atomic number) and the combined number of protons and neutrons (atomic mass) remain unchanged.
A rocket uses an engine that creates thrust through the combustion of a liquid fuel and an oxidizer. What kind of rocket is this?
The kind of rocket described is a liquid-fueled rocket.
Fuel and Oxidizer: The fuel and oxidizer are stored separately as liquids. Common examples are liquid hydrogen (fuel) and liquid oxygen (oxidizer).
Combustion: When the fuel and oxidizer are pumped into the combustion chamber, they mix and ignite to produce thrust. This reaction produces high-pressure gases that are expelled through the rocket nozzle, propelling the rocket forward.
Control: Liquid-fueled rockets can be throttled, shut down, and restarted, offering greater flexibility than solid-fueled rockets. This makes them ideal for missions requiring precise maneuvers.
Example: The Space Shuttle used liquid-fueled main engines that burned liquid hydrogen and liquid oxygen. In addition, it had solid rocket boosters that used a solid fuel mixture.
What happens to the mass of a sample containing a radioactive element during its half-life?
A. The mass decreases by half. B. The amount of mass is doubled. C. Eventually there is no mass at all. D. The mass remains the same.
OPTION A
The mass of a sample containing a radioactive element decreases to half its original value during its half-life, following an exponential decay pattern.
Explanation:During the half-life of a radioactive element, the mass of a sample containing this element decreases to half its original value. For instance, if we start with 100 grams of a radioactive isotope, after one half-life period, the sample will have decayed to provide 50 grams of the radioactive isotope. As time progresses and several half-lives pass, the amount present continues this pattern of reduction. After two half-lives, this amount will be 25 grams, and so on. This decay process follows what is known as exponential decay, where with each half-life, half of the remaining radioactive nuclei decay.
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Methane, CH4, burns in oxygen gas to form water and carbon dioxide. What is the correct balanced chemical equation for this reaction?
I'm having a hard time understanding how to balance a chemical equation. I'm really not sure how to even begin. Please help!