Atoms, Ions, and Isotopes

Which of the following statements correctly describes the difference between an atom and an ion?

• An atom has a different number of protons and neutrons, while an ion has the same number of protons and neutrons.

• An atom is electrically neutral, while an ion has a net positive or negative charge.

• An atom always has more electrons than protons, while an ion always has more protons than electrons.

• An atom is always unstable, while an ion is always stable.

Which of the following best describes an isotope?

• Atoms of the same element with different numbers of protons.

• Atoms of different elements with the same number of neutrons.

• Atoms of the same element with different numbers of neutrons.

• Atoms of the same element with different numbers of electrons.

If we are dealing with a neutral Sodium atom, how many electrons does it have?

• 10

• 11

• 12

• 23

Select the pair that are isotopes of each other from the following options:

• ¹²C and ¹⁴C

• ¹²C and ¹²N

• ¹⁴C and ¹⁴N

• ¹²N and ¹⁴N

Tags

NGSS.HS-PS1-8

A chlorine atom has 17 protons and 18 neutrons. What is its mass number?

• 17

• 18

• 35

• 34

Which of the following ions has the same number of electrons as a neutral neon atom (Ne)?

• Na+

• F−

• O2−

• Mg2+

Which statement best compares the structure of a Ca2+ ion to a neutral Ca atom?

• Ca2+ has two more electrons than a neutral Ca atom.

• Ca2+ has two fewer electrons than a neutral Ca atom.

• Ca2+ has two more protons than a neutral Ca atom.

• Ca2+ has two fewer protons than a neutral Ca atom.

Which of the following is true for all isotopes of a given element?

• They have the same number of protons.

• They have the same number of neutrons.

• They have the same mass number.

• They have the same number of electrons.

A neutral atom of magnesium (Mg) has 12 protons and 12 neutrons. What is its atomic number and mass number?

• Atomic number 12, mass number 24

• Atomic number 24, mass number 12

• Atomic number 12, mass number 12

• Atomic number 24, mass number 24

Tags

NGSS.MS-PS1-1

C and 12C are considered isotopes?

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

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

• They have the same number of neutrons but different numbers of electrons.

• They have different numbers of protons and electrons.