Average Atomic Mass Assessment

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

What does the 1.00794 stand for?

• Hydrogen
• atomic number
• atomic mass
• atomic explosion

Tags

NGSS.HS-PS1-1

What is the atomic number for an element with three protons?

• 2
• 1
• 3
• 6

An isotope has three forms.  30% have a mass of 4 amu, 20% have a mass of 5 amu and 50% have a mass of 3 amu.  Average atomic mass will be closest to

• 2 amu
• 3 amu
• 4 amu
• 5 amu

If an atom contains exactly three protons, then it's an atom of _____

• lithium
• gold
• nitrogen
• carbon

Tags

NGSS.HS-PS1-1

How many neutrons does the isotope of lithium have?

• 8
• 3
• 4
• 5

Tags

NGSS.HS-PS1-8

How many neutrons in C-14?

• 6
• 7
• 14
• 8

How many neutrons does an atom of the isotope Neon-22 have?

• 12
• 10
• 22
• 20

4.35% of all X atoms have a mass of 39.946 amu. 83.79% have a mass of 41.941 amu, 9.50% have a mass of 42.941 amu, and 2.36% have a mass of 43.939 amu. What is the average atomic mass of atom X?

• 41.97 amu
• 42.19 amu
• 10.43 amu
• 40.04 amu

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.
How many protons does this element have?

• 32
• 33
• 34
• no way to know