Atomic Number, Atomic Mass and Isotope Practice

The most common isiopte of gallium has a mass number ​ of ​ ​ (a)  

• 70
• 31
• 69

Tags

NGSS.MS-PS1-1

Match the following elements to the correct description

• noble gas

• chlorine, Cl

• has 9 electrons in a neutral atom

• fluorine, F

• most comon isotope has 6 neutrons

• neon, Ne

• most common isotope has a mass of 24

• magnesium, Mg

• has 17 protons in its nucleus

• carbon, C

Tags

NGSS.MS-PS1-1

Label the parts of the atom. Not all labels will be used!

a

b

c

d

e

neutron

nucelus

electron

electron cloud

compound

proton

Tags

NGSS.MS-PS1-1

Match the following descriptions to the best term

• element

• if you change the number of protons you get a different...

• protons & neutrons

• if you change the number of neutrons you get a different...

• nucleus

• these are in the nucleus

• neutrons

• an isotope has the same number of protons but a different number of...

• mass

• the mass of the atom is found here

Tags

NGSS.MS-PS1-1

The most common isotope of sodium has how many neutrons?

• 23

• 11

• 2, 8, 1

• 12

Tags

NGSS.MS-PS1-1

Label the following isotope symbol. Not all labels will be used!

a

b

c

Mass Number

Atomic number

Element Symbol

number of neutron

Tags

NGSS.MS-PS1-1

A certain atom of oxygen contains 8 protons, 8 neutrons, & 8 electrons. Another atom of unknown identity contains 9 protons. Which of the following MUST be true about this unidentified atom?

• It has 9 neutrons in its nucleus.

• It is an isotope of oxygen.

• Its atomic mass is a decimal number.

• It cannot be an atom of oxygen.

How many electrons does Potassium (K) have?

• 19

• 39

• 20

• 58

An element is identified by

• its number of protons

• the atomic mass

• the type of charge

• its number of isotopes

Tags

NGSS.MS-PS1-1

Atoms are neutral because the number of

• protons equals the number of neutrons

• protons equals the number of electrons

• neutrons is greater than the number of protons

• neutrons is greater than the number of electrons