Answer: 68.
Explanation:
The atomic number is the number that idenfities an element.
The atomic number is the number of protons of an element.
Every element has a different number of protons.
The elements are arranged in the periodic table as per their atomic number (number of protons).
The first element is hydrogen (H), its atomic number is 1, and it has 1 proton.
The second element is helium (He), its atomic number is 2 (it has 2 protons)-
Those two elements form the first period (row) of the periodic table.
The second row (period) has the elements Li, Be, B, C, N, O, F and Ne, whose respective atomic numbers (number of protons are) 3, 4, 5, 6, 7, 8, 9, and 10, respectively.
And so, you may idenfity each of the 118 elements known, with a different atomic number (number of protons).
D IS THE ANSWER TO YOUR QUESTION
Answer:
Hence the evaporation rate in pints per minute is 0.001583.
Explanation:
Now,
1.5 gallons of paint are used.
It has 5% solid, so total 95% of 1.5 gallon can evaporate(only the solvent part will evaporate).
95% of 1.5 gallon=(95/100)*1.5 = 1.425 gallons.
1gallon = 8 pints.
So 1.425 gallons=8*1.425 pints
=11.4 pints.
Evaporation requires 2 hours. That is 3600*2 seconds = 7200 seconds.
So evaporation rate= 11.4 pints/7200 seconds.
=0.001583 pints per second
<u>Answer:</u>
<em>20, 44, 62 </em>
<em></em>
<u>Explanation:</u>
To find the number of atoms of each element, we multiply coefficient and subscript
For example 
contains
5 × 1 = 5 ,Ca atoms and
5 × 2 = 10, Cl atoms
If there is a bracket in the chemical formula
For example 
we multiply coefficient × subscript × number outside the bracket to find the number of atoms
(Please note: 3 is the coefficient, and if there is no number given then 1 will be the coefficient )
So
3 × 3 = 9 , Ca atoms
3 × 1 × 2 = 6, P atoms
3 × 4 × 2 = 24, O atoms are present.
So let us find the number of atoms of each element on the left side of the equation
Number of C atoms = 2 × 10 = 20
Number of H atoms = 2 × 22 = 44
Number of O atoms = 31 × 2 = 62
20, 44, 62 are the Answers.
Most atoms have more neutrons than protons which accounts for basically half of the nucleuses mass.
