Answer:
On the placement of hydrogen and helium in the periodic system
H1=1
He2=2
Answer:
54
Barium atomic number is 56, this means that it has 56 protons in its nucleus and put it as a period 6 element. an uncharged barium atom would have 56 electron also. However as a group 2 element barium easily loses 2 electron to form the +2 cation. the ions has 56-2=54
The exponential is 3.007 times 10 to the -5
Blood cells, glucose , skin cells and etc .