Atomic Theory and Nuclear Processes

How many protons does an atom of Erbium (element Er, near the bottom of the periodic table) have?

You have an atom of Europium (element 63) that has 93 neutrons. What is the mass of this atom?

An atom of Mendelevium (Md, near the bottom of the table) has a mass of 262. How many neutrons does it have?

An atom has 49 protons, 47 electrons, and 68 neutrons. What is the overall charge of this atom?

• Positive

• Negative

• Neutral

What type of bird is this?

• Greater white-fronted goose

• American black duck

• Common Loon

• Mottled duck

Why do atoms usually become unstable?

• When they have too many electrons.

• When they have too many protons.

• When they have too many croutons.

• When they have too many neutrons.

When atoms undergo alpha decay, they will...

• Only lose two protons.

• Lose two protons and two neutrons.

• Gain two protons and two neutrons.

• Only lose two neutrons.

What type of bird is this?

• Worm-eating warbler

• Kentucky Warbler

• Connecticut Warbler

• Nashville Warbler

You have an atom of Californium-255 (Cf, element 98). What is the mass of this atom before it undergoes alpha decay?

Answer explanation

The mass is just 255. Do not use the mass on the periodic table.

How many protons does the atom of Californium-255 have?

Answer explanation

98. 98 - it is the same as the atomic number.