How do you know how many valence electrons an element has?

• Find in which period the element is located

• Find in which group the element is located

Answer explanation

A group have the same number of valence electrons and similar properties.

A group goes from _____ to _______.

• Top to bottom

• Left to right

On your periodic table you can find information in this format. Which number is the atomic number for Copper?

• 63.546

• 29

Answer explanation

The atomic number is determined by the number of protons. The mass is the average of all its isotopes. This is why mass number is not a whole number, but has decimals.

Tags

NGSS.MS-PS1-1

Draw the correct number of orbitals for Phosphorus (P).

Answer explanation

Phosphorus is in period 3, therefore you should draw three orbitals or electron shells.

Tags

NGSS.HS-PS1-1

Carbon and Silicon both have ______ of valence electrons.

Answer explanation

Both elements belong to group 14. They both have the same number of valence electrons in their outer shell.

Which element is a non-metal?

• Calcium (Ca)

• Hydrogen (H)

• Magnesium (Mg)

• Germanium (Ge)

Answer explanation

Hydrogen is in group one but belongs to the non-metals because it is a gas.

Tags

NGSS.MS-PS1-2

What is the charge of a proton?

• positive

• negative

• no charge

What is the charge of a neutron?

• Positive

• negative

• no charge

What is the charge of an electron?

• positive

• negative

• no charge

Tags

NGSS.MS-PS2-3

What is the charge of a proton, neutron, and electron respectively?

• +1, 0, -1

• 0, +1, -1

• -1, +1, 0

Answer explanation

respectively means individually and in the order given.