Question 1

Which law states that in a chemical reaction, matter is neither created nor destroyed, and the total mass of substances involved does not change?

Accepted Answer

The law of conservation of mass

Question 2

A sample of ammonia (NH$$_3) $$contains 10.0 grams of hydrogen. Given the nitrogen-to-hydrogen mass ratio in ammonia is 4.7:1, how many grams of nitrogen does the sample contain?

Accepted Answer

$$47$$ grams

Question 3

Which statement best distinguishes the law of definite proportions from the law of multiple proportions?

Accepted Answer

The law of definite proportions applies to two or more samples of the same compound, while the law of multiple proportions applies to two different compounds containing the same two elements.

Question 4

Which subatomic particle is responsible for the chemical properties of an element and is found outside the nucleus?

Accepted Answer

Electron

Question 5

How many neutrons are present in an isotope of argon with a mass number of 40 ($$A = 40) $$and atomic number $$Z = 18$$?

Accepted Answer

$$22$$

Question 6

Which element contains 50 protons in its nucleus?

Accepted Answer

Tin

Question 7

A neutral atom of sodium ($$^{23}_{11}Na) $$loses one electron. What is the resulting ion and its charge?

Accepted Answer

$$\mathrm{Na}^+$$, +1 charge

Question 8

Which region of the periodic table contains elements that are good conductors of heat and electricity, are malleable, ductile, and tend to lose electrons during chemical changes?

Accepted Answer

Metals

Question 9

Which group of elements is known for being highly unreactive and is often used in applications requiring chemical stability, such as filling balloons?

Accepted Answer

Noble gases

Question 10

Calculate the atomic mass of chlorine given the following data: 75.77% chlorine-35 (mass = 34.97 amu) and 24.23% chlorine-37 (mass = 36.97 amu). Use the formula $$	ext{Atomic mass} = \sum (	ext{fraction of isotope}) 	imes (	ext{mass of isotope}).$$

Accepted Answer

$$35.45$$ amu

Question 11

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 12

Which of the following ions is isoelectronic with neon ($$\mathrm{Ne}$$)?

Accepted Answer

$$\mathrm{Na}^+$$

Question 13

Which property is NOT characteristic of nonmetals?

Accepted Answer

Malleable and ductile

Question 14

A main-group element in group 6A is most likely to form which ion?

Accepted Answer

$$-2$$ anion

Question 15

Which of the following statements is TRUE regarding the modern periodic table?

Accepted Answer

Elements are arranged in order of increasing atomic number

Question 16

Which of the following is NOT a property of metals?

Accepted Answer

Tend to gain electrons during chemical changes

Question 17

A sample of water contains $$0.125 g $$hydrogen per $$1.00 g $$oxygen. A sample of hydrogen peroxide contains $$0.0625 g $$hydrogen per $$1.00 g $$oxygen. Show these results are consistent with the law of multiple proportions by calculating the ratio of hydrogen in water to hydrogen in hydrogen peroxide.

Accepted Answer

$$2:1$$

Question 18

Which of the following best describes the charge and location of a neutron?

Accepted Answer

No charge, inside the nucleus

Question 19

How many electrons are present in the $$\mathrm{O}^{2-}$$ anion?

Accepted Answer

$$10$$

Question 20

Which terms best apply to lead (Pb)?

Accepted Answer

Transition element; metal

Atoms and Elements: Foundations of Modern Chemistry

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