<u>Answer:</u> The given isotope of tin has 50 protons and 69 neutrons.
<u>Explanation:</u>
Atomic number is defined as the number of protons or number of electrons that are present in neutral atom. It is represented as Z.
Atomic number = Number of protons = Number of electrons
Mass number is defined as the sum of number of protons and number of neutrons. It is represented as A.
Mass number = Number of protons + Number of neutrons
We are given:
An isotope having representation 
Mass number of Sn = 19
Atomic number = 50
Number of neutrons = Mass number - Atomic number = 119 - 50 = 69
Hence, the given isotope of tin has 50 protons and 69 neutrons.
1) d
2) b because the independent variable is the thing you change/control in an experiment
3) c because the dependent variable is the thing being measured in an experiment
4)hmm it might be d, as c and a are both correct as different sized feeders would make it an unfair test and different types of food would as well
5) c
6) a
7) b obviously because if he activated them at different times then the ones activated last would have an advantage
Answer:
9988888888888888888886hgaWWZ6444
Explanation:
p [OH-] = -log[OH-]= -log ( 1x10^-11M) = 11
we know that
p[OH-] + p[H+] = 14
so p[H+] = 14- p[OH-] = 14- 11 = 3
pH = 3, answer
I believe that is condensation