Question 1

Which of the following statements best describes the difference between a scientific law and a scientific theory?

Accepted Answer

A law summarizes a series of related observations, while a theory gives the underlying reasons for them.

Question 2

A sample of water decomposes to produce 16.0 grams of oxygen and 2.0 grams of hydrogen. What is the mass ratio of oxygen to hydrogen in water?

Accepted Answer

$$8.0$$

Question 3

Which of the following is a heterogeneous mixture?

Accepted Answer

A mixture of sand and salt

Question 4

Which experiment led to the discovery of the electron?

Accepted Answer

Cathode ray tube experiment

Question 5

A neutral atom of chlorine has 17 protons and 18 neutrons. What is the isotope symbol for this atom?

Accepted Answer

$$^{35}_{17}\mathrm{Cl}$$

Question 6

Which law states that when two elements form two different compounds, the masses of one element that combine with a fixed mass of the other element are in a ratio of small whole numbers?

Accepted Answer

Law of multiple proportions

Question 7

A titanium cube contains $$2.15 	imes 10$$^{23}$$ atoms. The density of titanium is 4.50$$\ \mathrm{$$g/cm^3$$}$$. What is the first step to find the edge length of the cube?

Accepted Answer

Convert the number of atoms to moles using Avogadro’s number.

Question 8

Which of the following best describes an isotope?

Accepted Answer

Atoms with the same number of protons but different numbers of neutrons.

Question 9

A pure silver ring contains $$2.80 	imes 10$$^{22}$$ silver atoms. How many moles of silver atoms does it contain? (N_A = 6.022$$ 	imes $$10^{23}$$\ \mathrm{mol}^{-1}$$)

Accepted Answer

$$0.0465\ \mathrm{mol}$$

Question 10

Which sample contains the most atoms: 1 g of copper, 1 g of carbon, or 1 g of uranium?

Accepted Answer

1 g of carbon

Question 11

Which of the following statements is true regarding the nuclear model of the atom?

Accepted Answer

For a given element, the size of an atom is the same for all the element’s isotopes.

Question 12

Which of the following is a compound?

Accepted Answer

Water

Question 13

A sample of carbon monoxide produces 17.2 grams of oxygen and 12.9 grams of carbon. Another sample produces 10.5 grams of oxygen and 7.88 grams of carbon. Are these results consistent with the law of definite proportions?

Accepted Answer

Yes, because the mass ratios of oxygen to carbon are equal in both samples.

Question 14

Which of the following is NOT a characteristic of a scientific hypothesis?

Accepted Answer

It is a summary of past observations.

Question 15

How many electrons are in the $$\mathrm{N}^{3-}$$ anion?

Accepted Answer

$$10$$

Question 16

Naturally occurring chlorine consists of 75.77% chlorine-35 (mass 34.97 amu) and 24.23% chlorine-37 (mass 36.97 amu). What is the atomic mass of chlorine?

Accepted Answer

$$35.45\ \mathrm{amu}$$

Question 17

Which of the following is a property of gaseous matter?

Accepted Answer

Atoms or molecules are free to move relative to one another and have a lot of space between them.

Question 18

Which element contains 50 protons in its nucleus?

Accepted Answer

Tin

Question 19

A sample of ammonia contains 10.0 g of hydrogen. If the mass ratio of nitrogen to hydrogen in ammonia is $$14:3$$, how many grams of nitrogen does it contain?

Accepted Answer

$$14$$

Atoms and the Structure of Matter: Chapter 1 Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard