Radioactivity was discovered by

1. The lifespan of Red Blood Cells is __________ days.

A. 60
B. 120
C. 180
D. 240

2. The density of water is __________.

A. 1 g/cm3

B. 1.5 g/cm3
C. 2 g/cm3
D. none of these

3. Radioactivity was discovered by __________.

A. Kelvin
B. Thomson
C. Rutherford

D. Bacquerel