Light and Electrons

What is the mass number of He

What is the atomic number of He

How many protons neutrons and electrons are in this helium isotope?

• 2 protons, 2 neutrons, 2 electrons
• 4 protons, 2 neutrons, 2 electrons
• 0

Where does the average atomic mass come from for hydrogen?

• number of protons and netrons in a single isotope
• weighted average of all isotopes of hydrogen
• amu of the electrons
• average mass of protons plus electrons

Where do elements like Beryllium-8 come from? Use helium as an example.

• Fusion between another helium give us 4 protons and 4 neutrons (beryllium - 8)
• Fusion between another helium give us 4 protons and 8 neutrons (beryllium - 8)
• Fission between another helium give us 2 protons and 2 neutrons (beryllium - 4)
• Fusion between another hydrogen give us 4 protons and 4 neutrons (beryllium - 8)

What does the number 91 represent in the name zirconium-91?

• the atomic number
• the number of protons
• the mass number
• the sum of protons and electrons

Which of the following sets is correct?

• Zn-65, 65 protons, 65 electrons
• Mg-24, 12 protons, 12 neutrons
• U-238, 92 protons, 92 neutrons
• Pb-207, 207 protons, 207 electrons

An atom has an atomic number of 32 and a mass number of 73, How many protons, neutron, and electrons does this neutral atom contain

• 32 p, 73 n, 32 e
• 73 p, 73 n, 41 e
• 32 p, 41 n, 32 e
• 41 p, 32 n, 41 e

Identify the element that has 31 neutrons and a mass of 59

• gallium
• praseodymium
• thorium
• nickel

Which statement about isotopes is true?

• Isotopes have different chemical properties
• Isotopes have different atomic numbers
• Isotopes have different numbers of electrons
• Isotopes have different masses