$$\text{ion charge} = \text{number of protons} - \text{number of electrons}$$

Question 1

Which statement best describes John Dalton's atomic theory as it relates to the formation of compounds?

Accepted Answer

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

Question 2

Which experiment led to the discovery that most of the atom's mass is concentrated in a small, dense nucleus?

Accepted Answer

Rutherford's gold foil experiment

Question 3

If a neutral atom of sodium (Na) has 11 protons and 11 electrons, what is its charge after it loses one electron?

Accepted Answer

$$+1$$

Question 4

Which property is NOT characteristic of metals?

Accepted Answer

Tends to gain electrons in chemical reactions

Question 5

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

Accepted Answer

$$	ext{ion charge} = 	ext{number of protons} - 	ext{number of electrons}$$

Question 6

A chlorine atom has 17 protons and 18 electrons. What is the charge of the resulting ion?

Accepted Answer

$$-1$$

Question 7

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

Accepted Answer

Carbon

Question 8

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

Accepted Answer

$$A = 31$$

Question 9

Which group of elements is known for being chemically inert and not forming compounds easily?

Accepted Answer

Noble gases

Question 10

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

Accepted Answer

$$69.72\ 	ext{amu}$$

Question 11

Which scientist is credited with organizing the periodic table based on recurring properties and increasing relative mass?

Accepted Answer

Dmitri Mendeleev

Question 12

Which of the following is a real-world application of radioactive isotopes in medicine?

Accepted Answer

Using technetium-99 to diagnose disease

Question 13

Which element's symbol is derived from its Latin name 'natrium'?

Accepted Answer

Na

Question 14

Which property is characteristic of metalloids?

Accepted Answer

They have intermediate electrical conductivity that can be controlled.

Question 15

What is the correct isotope symbol for neon with 10 protons and 12 neutrons?

Accepted Answer

$$^{22}_{10}	ext{Ne}$$

Question 16

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

Accepted Answer

Lightning is caused by the imbalance of positive and negative charges in matter.

Question 17

Which element is named after a scientist who won two Nobel Prizes and helped discover radioactivity?

Accepted Answer

Curium

Question 18

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 19

Which group in the periodic table contains elements that react violently with water?

Accepted Answer

Alkali metals

Question 20

A fluorine atom gains one electron during a chemical reaction. What is the resulting ion called?

Accepted Answer

Fluoride anion

Atoms and Elements: Foundations of Atomic Theory and the Periodic Table

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