Carbon-14 has a half-life of 5730 years after how many half lives will 120 g of carbon-14 decay to 15 g

a. one

b. two

c. three

d. four

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

spectral lines lyman is one set