Atomic Structure and Average Atomic Mass

A neutral atom of Carbon-13 has ________ electrons and _________ neutrons

• 13, 13
• 6, 7
• 7, 7
• 6, 6

What is true about a neutral atom?

• The number of protons equal the number of neutrons
• The number of protons equal the number of electrons
• The number of neutrons equal the number of electrons
• The number of protons, neutrons, and electrons are all different

Tags

NGSS.HS-PS1-7

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

Oxygen has 8 protons. What is oxygen's atomic number?

• 16
• 8
• 15.999
• 0

Isotopes are atoms of the same element that have the same number of __________ but different number of __________ . Therefore, isotopes of the same element have different masses. 

• protons, neutrons
• protons, electrons
• neutrons, protons
• electrons, protons

Nitrogen has three occurring isotopes: Nitrogen-13, Nitrogen-14, Nitrogen-15. Which isotope is the most abundant?

• Nitrogen-13
• Nitrogen-14
• Nitrogen-15
• Based on the information given, it cannot be determined

The number in the upper corner of an element tile (7 for nitrogen) is called _____

• the proton number
• the atomic number
• the electron number
• the mass number

Tags

NGSS.HS-PS1-1

For a given element, the atomic number indicates the number of _____

• protons in the nucleus
• neutron in the nucleus
• electrons in the atom
• nucleons in the atom

Tags

NGSS.MS-PS1-1

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

• lithium
• gold
• nitrogen
• carbon

Tags

NGSS.HS-PS1-1

The sum of the number of protons and the number of neutrons is called the _____

• atomic number
• mass number
• isotope number
• average weight

Tags

NGSS.MS-PS1-1