Trur or false 1.i the periodic table most element are non-metal
2. an element with atomic number 14 is found in group lllA and period 5
3. element in the same number of shells

that is the periodic table

1) false, from group 1 - group 3 are metals (there are 9 elements) and , from group 4 - group 8 are non metals ( there 11 elements)

2) false, the 14th element is silicon which is in group 4 and is period 3.

3) I don't understand

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.