If there are 49 grams of U-238 on day zero of radioactive decay, how much will there be after 4.5 billion years? a.
98

b.
24

c.
163

d.
12

It would be true sodium reacts with water in a violent way 

Answer(2) electrons;

A)  it is neutral because the concentration of hydronium ions equals that of hydroxide ions

Van der waals forces are temporary electromagnetic forces established between uncharged atoms. some neutral molecules, when close together, can become temporarily “charged,” as electrons move around the atom. water is a polar molecule, the side of the molecule that the hydrogens bond to being more positive, and the opposite side bound to the lone pairs of electrons being more negative. this means that it participates in dipole-dipole interaction (non-polar exhibits dispersion forces), and it has the capacity for hydrogen bonding.