$$\text{Charge} = \text{Number of protons} - \text{Number of electrons}$$

Question 1

Which experiment led to the rejection of the plum-pudding model of the atom and the development of the nuclear model?

Accepted Answer

Rutherford's gold foil experiment

Question 2

According to Dalton’s atomic theory, which statement is TRUE?

Accepted Answer

Atoms combine in simple, whole-number ratios to form compounds.

Question 3

Which subatomic particle has a nearly negligible mass compared to the others?

Accepted Answer

Electron

Question 4

What is the charge of an ion with 11 protons and 10 electrons?

Accepted Answer

$$+1$$

Question 5

Which property is NOT characteristic of metals?

Accepted Answer

Tend to gain electrons in chemical reactions

Question 6

How is the atomic mass of an element calculated when it has multiple isotopes?

Accepted Answer

By calculating the weighted average of the isotopic masses using their fractional abundances

Question 7

Which group in the periodic table contains elements that are chemically inert?

Accepted Answer

Noble gases

Question 8

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

Accepted Answer

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

Question 9

Which element is defined by having 6 protons in its nucleus?

Accepted Answer

Carbon

Question 10

Which statement best describes the location and charge of electrons in the nuclear model of the atom?

Accepted Answer

Electrons are dispersed in a cloud around the nucleus and have a negative charge.

Question 11

Which element is a metalloid and is widely used in the electronics industry?

Accepted Answer

Silicon

Question 12

If an atom has 12 protons, 12 neutrons, and 10 electrons, what is its charge and element?

Accepted Answer

Magnesium, charge $$+2$$

Question 13

Which of the following is a real-world example of a radioactive isotope used in medicine?

Accepted Answer

Technetium-99

Question 14

What is the mass number ($$A) of an $$isotope with 15 protons and 16 neutrons?

Accepted Answer

$$A = 31$$

Question 15

Which element is named after a scientist who contributed to the discovery of radioactivity?

Accepted Answer

Curium

Question 16

A sample of gallium contains 60.11% Ga-69 (68.9256 amu) and 39.89% Ga-71 (70.9247 amu). What is the atomic mass of gallium?

Accepted Answer

$$69.72\ 	ext{amu}$$

Question 17

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 18

Which group of elements tends to gain electrons in chemical reactions?

Accepted Answer

Nonmetals

Question 19

What is the formula for calculating the charge of an ion?

Accepted Answer

$$	ext{Charge} = 	ext{Number of protons} - 	ext{Number of electrons}$$

Question 20

Which of the following best explains why lightning occurs during an electrical storm?

Accepted Answer

The quick rebalancing of charge between clouds and the ground

Atoms and Elements: Foundations of Chemistry

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