Atoms and Periodic Table

Dmitiri Mendeleev created the first periodic table by organizing the elements by atomic _______. It is no longer organized this way.

• mass (or weight)

• metals and nonmetals

• atomic number

• He was not the creator

Our present day periodic table is organized by

• valence electrons

• Atomic mass (or weight)

• number of neutrons

• Atomic Number

The columns ↕ on the periodic table are called

• periods
• valence electrons
• groups (or families)
• gatherings

The rows ↔ on the periodic table are called

• gatherings
• valence electrons
• groups (or families)
• periods

If elements share similar properties, then they will be in the same group and have the same number of

• neutrons
• valence electrons
• protons
• periods

What group/family of elements has a full outer shell of electrons?

• Group 2/alkaline earth metals
• Group 1/alkali metals
• Group 17/halogens
• Group 18/noble gases

What group/family of metal elements is the most reactive?

• Group 2/alkaline earth metals
• Group 1/alkali metals
• Group 17/halogens
• Group 18/noble gases

If a balanced atom of Oxygen has an atomic number of 8 and an atomic mass of 16. Then it will have ____ protons, ____electrons, and ____ neutrons.

• 16 protons 16 electrons 16 neutrons
• 8 protons 8 electrons 8 neutrons
• 16 protons 16 electrons 8 neutrons
• 8 protons 8 electrons 16 neutrons

When you rubbed the balloon on your clothes/hair it collected ___________ charges.

• neutral
• positive
• negative
• no

Like charges (++ or - -) __________ while opposite charges (+ -) __________.

• repel attract
• attract repel
• attract attract
• repel repel