1 What group and period does this element belong in? A periodic cable is needed to answer this question
1. period 1 and group 3
2. period 2 and group 3
3. period 3 and group 1
4. period 3 and group 2

I believe the answer to be period 3 group 1

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements