Answer:
Multiple choice answer would be "None"
Explanation:
White dwarfs are radiating stored heat from earlier reactions.
Technically, it would be the last fusion stage the star went through
BEFORE it became a white dwarf, but that's nit-picking.
Answer: The correct answer would be C. Salt crystals are hard and brittle because they are made up of atoms that combine by ionic bonding.
Explanation: All the other ones are chemical changes because a new substance is formed.
Electrons circle the outside of the nucleus.
Answer:
[H3O+] = 0.00520 M
Explanation:
The dissociation of acetic acid in water is given by the equation;
CH3COOH + H2O<-------> H3O+ + CH3COO-
ka = [H+][C2H3O2-]/[HC2H3O2]
Ka = 1.8 x 10^-5
= x^2 / 0.150-x
x = [H3O+]= 0.00520 M