Has a mass of $$1.6749 \times 10$$^{-27}$$ kg and no electric charge

Question 1

Which subatomic particle determines the atomic number ($$Z) of an $$element?

Accepted Answer

Proton

Question 2

A neutral atom of calcium ($$Ca) $$has 20 protons and 20 neutrons. What is its mass number ($$A$$)?

Accepted Answer

$$A = 40$$

Question 3

Which of the following statements is TRUE about isotopes?

Accepted Answer

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

Question 4

A silicon ($$Si) $$atom has a charge of $$2+. If $$its atomic number is 14, how many electrons does it have?

Accepted Answer

12 electrons

Question 5

Which of the following best describes a neutron?

Accepted Answer

Has a mass of $$1.6749 	imes 10$$^{-27}$$ kg and no electric charge

Question 6

An atom contains 20 protons, 18 electrons, and 21 neutrons. What is its nuclear symbol and charge?

Accepted Answer

$$^{41}_{20}Ca$$^{2+}$$

Question 7

Which isotope of carbon is used in radiocarbon dating?

Accepted Answer

$$^{14}C$$

Question 8

If an atom has 35 neutrons and 25 protons, what is its mass number ($$A$$)?

Accepted Answer

$$A = 60$$

Question 9

Which of the following is TRUE for a neutral atom?

Accepted Answer

Number of protons equals number of electrons

Question 10

A selenium ($$Se) $$atom has a charge of $$4-. If $$its atomic number is 34, how many electrons does it have?

Accepted Answer

38 electrons

Question 11

Which subatomic particle is responsible for the chemical properties of an element?

Accepted Answer

Electron

Question 12

Which of the following is the correct formula for calculating the mass number ($$A) of an $$atom?

Accepted Answer

$$A = Z + N$$

Question 13

Which statement about protons is correct?

Accepted Answer

Protons are composed of 2 up quarks and 1 down quark

Question 14

Which isotope of hydrogen is radioactive and used in PET scans?

Accepted Answer

Tritium

Question 15

What is the charge of an ion with 17 protons and 18 electrons?

Accepted Answer

$$1-$$

Question 16

Which of the following is NOT a property of electrons?

Accepted Answer

Composed of up and down quarks

Question 17

Which of the following best explains why all atoms of the same element have the same chemical behavior?

Accepted Answer

They have the same number of electrons

Question 18

A neutral atom of sodium ($$Na) $$has 11 protons. How many electrons does it have?

Accepted Answer

11 electrons

Question 19

Which of the following is a correct statement about ions?

Accepted Answer

Cations have fewer electrons than protons

Question 20

Which isotope of carbon is most abundant in nature?

Accepted Answer

$$^{12}C$$

Fundamentals of Chemical Elements, Atoms, and Ions

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