Atomic Theory and the Periodic Table

What is each horizontal row called?

• group
• family
• period

What did Democritus, Dalton, Thomson, Rutherford, and Bohr all have in common?

• Identified new isotopes
• contributed to the development of the atomic theory
• conducted experiments where particles collided

The smallest particle into which an element can be divided and still be the same substance

• neutron
• atom
• electron

Where are electrons likely to be found in the Modern Atomic Theory?

• the nucleus
• electron clouds
• neutrons

According to Rutherford, what was in the center of an atom?

• an electron
• a nucleus
• a particle

An atom of carbon with 6 protons, 6 electrons, and 6 neutrons would have an atomic mass of ?

• 15
• 12
• 21

What are most of the elements in the periodic table?

• metals
• metalloids
• precious metals

Particle that cannot be cut

• atom
• electron shells
• neutron

negatively charged particle

• proton
• neutron
• electron

central region (middle) of the atom

• protons
• nucleus
• electron clouds