Atomic Theory

Which is not true for isotopes?

• they are atoms with the same number of protons

• they are atoms with the same number of neutrons

• they are atoms of the same element type

• they are atoms with differing masses

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 is the name of the atom pictured here?

• Nitrogen
• Nitrogen-15
• Nitrogen-7
• Nitrogen-8

Which of the following could have 82 neutrons?

• W-182
• Ta-181
• Cs-132
• Ba-138

Which of the following could have 82 neutrons?

• W-182
• Ta-181
• Cs-132
• Ba-138

How many protons does Lithium have?

• 3
• 4
• 6
• 7

How many neutrons does an atom of Boron have?

• 5
• 6
• 10
• 11

which atom has  4 neutrons?

• Li-6
• Li-7
• Li-8
• they have the same # of neutrons

Where are electrons located in the atom?

• Nucleus
• Shells/orbitals
• rings
• center

If an atom loses an electron, does the atom become more positive or more negative?

• more positive
• more negative
• both
• neither