Answer: 14 Explanation: Mass number: the total number of protons and neutrons in a nucleus.
Mass number = Protons + Neutrons
=
6
+
8
=
14
D has the fastest reaction rate because dynamite explodes almost immediately.
A isn't correct because rusting nails take forever to completely rust.
B isn't correct because logs burning can take around 10 to 20 minutes.
C isn't correct because food digestions takes anywhere between 10 minutes to an hour.
The answer is each indicator has a narrow range. We need many different indicators to span the entire ph spectrum because each indicator has a narrow range.
The ostrich runs 21 N then goes back by 25 S
The displacement is -4 S
21 - 25 = -4
I think it would be these three answers ionic , covalent , and polar covalent
