Atomic number and mass number

What does the atomic number of an element represent?

• The number of protons in an atom

• The total number of protons and neutrons in the nucleus

• The number of neutrons in an atom

• The number of electrons in an atom

How can the number of neutrons in an atom be calculated?

• Atomic number + Mass number

• Mass number / Atomic number

• Mass number - Atomic number

• Atomic number - Mass number

What is true about the charge of protons and electrons?

• Protons and electrons both have a positive charge

• Protons have a negative charge, and electrons are neutral

• Protons are neutral, and electrons have a positive charge

• Protons have a positive charge, and electrons have a negative charge

Tags

NGSS.MS-PS2-3

What are isotopes?

• Atoms of different elements with the same number of protons

• Atoms of the same element with different numbers of electrons

• Atoms of different elements with the same number of neutrons

• Atoms of the same element with different numbers of neutrons

How many protons does an atom of lithium have?

• 4

• 7

• 3

• 6

What is the mass number of lithium?

• 10

• 7

• 4

• 3

What defines a positive ion?

• An atom that has gained electrons

• An atom that has gained protons

• An atom that has lost protons

• An atom that has lost electrons

How many electrons does a sodium ion with a single positive charge have?

• 9

• 10

• 11

• 12

What is the number of neutrons in the first isotope of chlorine mentioned?

• 20

• 17

• 15

• 18

How many electrons does the oxide ion with a two negative charge have?

• 10

• 6

• 8

• 12

Tags

NGSS.MS-PS1-1