Isotopes 2

Which subatomic particle determines the identity of an element?

• proton

• neutron

• electron

• boron

An atom with 19 protons, and 19 electrons and a mass of 39 has how many neutrons?

• 19
• 39
• 20
• 58

Tags

NGSS.MS-PS1-1

How many electrons does a Copper atom have?

• 63
• 29
• 92
• 34

Tags

NGSS.HS-PS1-1

How many neutrons does this isotope of lithium have?

• 8
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

Although carbon's three isotopes are carbon-12, carbon-13, and carbon-14, its average atomic mass is 12.01 because

• Carbon-12 is the heaviest isotope
• Carbon-12 is the most useful to humans
• Carbon-12 is the most common isotope

An element with 11 protons, 11 electrons, and 12 neutrons is identified as

• sodium - 11

• magnesium - 12

• sodium - 23

• magnesium - 34

Tags

NGSS.MS-PS1-1

Atoms of the same element which have a different number of neutrons are called _________________.

• ions

• isotopes

• quarks

• molecules

24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

• 74.92 amu
• 24.97 amu
• 75.01 amu
• 74.51 amu

A neutral atom of chlorine-35 can be described as the following EXCEPT

• contains 17 protons

• contains 35 electrons

• contains 18 neutrons

• has a mass of 35 amu

Tags

NGSS.MS-PS1-1

Vitellium (Vi) has the following composition:

Vi–188: 187.9122 amu; 10.861%

Vi–191: 190.9047 amu; 12.428%

Vi–193: 192.8938 amu; 76.711%

Based on this data, what can you predict about the average atomic mass of vitellium?

• It will be equal to the arithmetic mean of the masses of the three isotopes.

• It will be closer to the mass of Vi–188.

• It will be closer to the mass of Vi–193.

• It will be equal to the mass of Vi–193.