Periodic Table

What element is in Period 4, Group 2?

What element is in Period 1, Group 1?

How many orbitals, electron shells, or energy levels does Sodium (Na) have?

How many valence electrons does Magnesium (Mg) have?

What is the Mass Number of Silicon (Si)?

What element has the Chemical Symbol of K?

What is the chemical symbol for iron?

How many protons does an atom of Krypton (Kr) have?

How many electrons are there in a neutral atom of Iodine (I)?

How many neutrons are in an atom of Helium (He)?