All categories

2 years ago

Select the correct answer.

Chemistry

1 answer:

hichkok12 [17]2 years ago

6 0

Answer:

A. The model could not explain how alpha particles could be deflected at large angles.

Explanation:

The plum pudding model of the atom was proposed by J. J Thomson. He suggested that that an atom is made up of dense particles of electrons surrounded by positive charges.

From the Gold foil experiment carried out by Ernest Rutherford, he noticed that the bulk of the alpha particles targeted at the foil passed through and a little fraction was heavily deflected back.

Rutherford then presented his nuclear model from here. He suggested a massive, dense and tiny nucleus where the protons and neutrons are located. The space outside the mass is dominated by orbiting electrons.

You might be interested in

Which of the following would be the best representation of input energy and then

Rom4ik [11]

A is the correct answer

4 0

2 years ago

Why is a homogeneous mixture not considered a pure substance? Question 6 options: A pure substance can be separated by physical

krok68 [10]

1. Why is a homogeneous mixture not considered a pure substance?

Answer:

A pure substance can be separated by chemical means, while a mixture can be separated by physical means.

2. What is true if mass is conserved in a reaction?

Answer:

There are equal numbers of atoms on both sides.

3. Methane reacts with oxygen then what are the products?

Answer:

carbon dioxide and water

4. Which one of the following is not a homogeneous mixture?

Answer:

vegetable soup

5. The substance is not uniform in appearance and each part of the mixture contains a combination of different ingredients in different ratios.

Answer:

heterogeneous mixtures

6. If a solution is saturated, which of these is true?

Answer:

More solvent can be dissolved

7. Which of these substances are molecules?

Answer:

All compounds are molecules but not all molecules are compounds. Molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element. So correct option is 3 and 4.

8. What makes a solution a homogeneous mixture?

Answer:

It is uniform in composition.

9. When a solute is added to a solution, why does it remain homogeneous?

Answer:

The solute dissolves.

10. The chemical formula of glucose is C6H12O6, so it is classified as a(n)

Answer:

pure substance.

11. How many chlorine (Cl) atoms would be in 4 molecules of salt (4 NaCl)?

Answer:

12. In a solution of salt and water, which component is the solute?

Answer:

Salt

13. These substances are all H2O2, Li , NaCl , O2

Answer:

Pure Substances

14. If you have 5 grams of product after a chemical reaction, how many grams of reactants did you have at the start of the reaction?

Answer:

15. What is the difference between a compound and a mixture?

Answer:

A compound is a pure substance, but a mixture is not.

16. A firework exploding would be an example of a(n) ________.

Answer:

Exothermic reaction

17. If Lavoisier heated 100 grams of powdered mercuric oxide to produce 93 grams of liquid mercury, how much oxygen would be released?

Solution

2HgO ==> 2Hg + O2

Mass of HgO = 100 g

Molar mass of HgO = 216.59 g/mol

Moles = mass/molar mass = 0.46 moles

From balance chemcial equation

HgO : O2

2 = 1

0.46 = (1 × 0.46 ) ÷ 2 = 0.23 moles

mass of O2 = moles× molar mass = 0.23 × 32 = 7.36 g

18. Using the Law of Conservation of Matter, determine the number of grams of iron sulfide (FeS) that will be produced in this reaction.

Solution

12g Fe + 64g S → _____ g FeS

According to Law of Conservation of Matter, The total mass of reactant is equal to total mass of product , so the number of grams of iron sulfide (FeS) that will be produced in this reaction as follow.

12 + 64 = 76 g of FeS

Hope this Help.

3 0

3 years ago

Read 2 more answers

A 100.-gram sample of H2O(l) at 22.0°C absorbs 830. joules of heat. What will be the final temperature of the water? Hurry pleas

k0ka [10]

Answer:

That is extremely confusing. Try contacting your prof.

Explanation:

4 0

2 years ago

Chemical reaction to form products this chemical equation represents one such reaction the coefficient for one of the reactants

Dmitriy789 [7]

Answer:

In a chemical equation, chemicals that react are the reactants, while chemicals that are produced are the products/by products. Both sides of the equation must be balanced.

Explanation

When writing a chemical equation, reactants reacts to produce products. For example in the equation for formation of water, hydrogen combines with oxygen as 2H₂ +O₂→2H₂O where the first part before the arrow represent the reactants and the next part after the arrow are the products. Reactants are on the left where as products are on the right.Coefficient 2, in this cases is used for balancing the equation

4 0

3 years ago

The term El Nino/Southern Oscillation refers to the occurrence of warmer than normal sea surface temperatures in the Eastern Pac

Amiraneli [1.4K]

Answer:

True

Explanation:

The El Nino/Southern Oscillation occurs in between the three phases Neutral, La Nina or El Nino.

The humboldt current takes cold water to South America's west coast to the tropics from the Southern Ocean. Because of the welling which takes place in Peru this process is enhanced. Due to the trade winds near the equator the cold water travels west where it heats up due to the sun. This makes the water of the western Pacific warmer.

6 0

3 years ago