Question 1

According to Dalton's atomic theory, which of the following statements is correct?

Accepted Answer

Atoms of a given element are identical in mass and properties.

Question 2

Which subatomic particle has a mass of approximately $$1.007 \ 276$$ amu and a charge of $$+1$$?

Accepted Answer

Proton

Question 3

An atom of carbon-14 is represented as $$^{14}_{6}C. $$How many neutrons does it contain?

Accepted Answer

$$8$$

Question 4

Which of the following best describes the charge and location of electrons in an atom?

Accepted Answer

Electrons are negatively charged and occupy the volume around the nucleus.

Question 5

A neutral atom of fluorine has an atomic number $$Z = 9$$ and a mass number $$A = 19. $$How many protons, neutrons, and electrons does it have?

Accepted Answer

$$9$$ protons, $$10$$ neutrons, $$9$$ electrons

Question 6

Which of the following is true about isotopes of an element?

Accepted Answer

They have the same number of protons but different numbers of neutrons.

Question 7

If an atom has $$17$$ protons, $$18$$ neutrons, and $$17$$ electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number $$17$$, mass number $$35$$

Question 8

Which subatomic particle is responsible for the identity of an element?

Accepted Answer

Proton

Question 9

A sample of neon contains atoms with $$10$$ protons, $$10$$ electrons, and $$12$$ neutrons. What is the isotope symbol for this atom?

Accepted Answer

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

Question 10

Which of the following statements about subatomic particles is correct?

Accepted Answer

Neutrons have no charge and a mass slightly greater than protons.

Question 11

A hospital uses a radioactive isotope of iodine, $$^{131}_{53}I$$, for thyroid imaging. How many neutrons are in one atom of this isotope?

Accepted Answer

$$78$$

Question 12

Which of the following best explains why atoms are electrically neutral?

Accepted Answer

They have equal numbers of protons and electrons.

Question 13

A sodium atom has an atomic number $$Z = 11$$ and a mass number $$A = 23. If it $$loses one electron to form a $$Na^+$$ ion, how many protons, neutrons, and electrons does the ion have?

Accepted Answer

$$11$$ protons, $$12$$ neutrons, $$10$$ electrons

Question 14

Which of the following is the correct symbol for an atom with $$20$$ protons and $$22$$ neutrons?

Accepted Answer

$$^{42}_{20}Ca$$

Question 15

Which property of an atom is determined by the number of protons in its nucleus?

Accepted Answer

Atomic number

Question 16

A patient receives a dose of technetium-99m ($$^{99m}_{43}Tc) $$for a medical scan. How many electrons are present in a neutral atom of this isotope?

Accepted Answer

$$43$$

Question 17

Which of the following best describes the difference between mass number and atomic number?

Accepted Answer

Mass number is the sum of protons and neutrons; atomic number is the number of protons.

Question 18

Which of the following real-world scenarios best illustrates the concept that chemical reactions only rearrange atoms, not change them into other elements?

Accepted Answer

Burning wood produces carbon dioxide and water, but the carbon atoms remain carbon.

Atoms and Subatomic Particles: Fundamentals of GOB Chemistry (Sections 2.1–2.2)

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