Practice for atoms, half-life, and bonding

Name (First and last)

Class Period

• 1
• 3
• 4
• 5
• 7

The process by which a nucleus splits into two or more fragments and releases neutrons and energy.

• Fission
• Half-life
• Fusion

The process in which light nuclei combine at extremely high temperatures, forming heavier nuclei and releasing energy.

• Fission
• Chain Reaction
• Half-life
• Fusion

Sodium-24 has a half-life of 24 hours. How much Sodium-24 will remain in an 100g sample after 48 hours?

• 10.0 g
• 25 g
• 100 g
• 50 g

Which of the following determine the chemical properties of elements?

• the number of valence electrons
• the number of neutrons
• the number of isotopes
• the number of protons

A sodium ion, Na+, has a positive charge because it

• Gained an electron
• Lost a proton
• Gained a neutron
• Lost an electron

Which of the following is true about an atom with the charge of +1?

• It has lost 1 proton
• It has lost 1 electron
• It has gained 1 proton
• It has gained 1 electron

Potassium's atomic number is 19. It has 20 neutrons, 19 electrons and a mass of 39. Give the symbol for potassium.

• P
• K
• Na
• Po

Carbon has an atomic number of 6. Carbon-14 is a naturally occurring isotope of carbon. How many neutrons are in carbon-14?

• 6
• 2
• 8
• 28