Most of the light passes through glass but none of the light passes through metal.
To calculate the atomic mass<span> of a single </span>atom<span>, add up the </span>mass<span> of protons and neutrons.
So, your answer would be A) add the number of protons and neutrons</span>
2.0 g 1.0g 0.5g 0.25g
3 and a half lives = 42 days
<span>these include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.</span>
