39. Determine the number of moles of compound in each of the following samples. (Hint: See Sample
Problem 1-13).
a. 4.50 g H2O
b. 471.6 g Ba(OH)2
C. 129.68 g Fe3(PO4)2
40. Determine the percentage composition of each
of the following compounds. (Hint: See Sample
Problem 1-14).
b. AgNO3
.c. Mg(OH)2
a. NaCl

Help me please for this two question

George is a dalmatian puppy. describe what happens to light that allows you to see george’s black and white coat.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Imagine that a new planet is discovered with two moons of equal mass: moon a and moon b. the mass of the new planet is greater than the combined mass of its moons. moon a is farther away from the new planet than moon b. what is the planet's gravitational pull on moon a compared to the planet's gravitational pull on moon b? the planet's gravity repels moon a with a greater force than it repels moon b, which is why moon a is farther away. the gravitational pull on moon b is greater than on moon a because moon b is closer to the new planet than moon a. the gravitational pull on moon b is greater than on moon a because moon b is farther away from the new planet than moon a. the gravitational pull on moon a is the same as the gravitational pull on moon b because distance does not affect the planet's gravity.