It will be Oxygen . And total 8 protons, 8 electrons and 9 neutrons are present in it.
Answer: 
is a reactant; it is present before the reaction occurs.
Explanation:
In a chemical reaction the chemical formulas written before the arrow are described as reactants as they react together to form products which are written after the arrow.
Thus and HCl are reactants here whereas 
, 
and 
are products.
The correct answer is C: the alkaline earth metals!
0.34 moles of gas would be contained in a 11.2 L container that is at a pressure of 0.75 atm and 300 K.
<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>
The number of moles of a substance can be calculated using the following expression:
PV = nRT
Where;
- p = pressure (atm)
- v = volume (L)
- n = number of moles
- R = gas law constant
- T = temperature
0.75 × 11.2 = n × 0.0821 × 300
8.4 = 24.63n
n = 8.4 ÷ 24.63
n = 0.34 moles
Therefore, 0.34 moles of gas would be contained in a 11.2 L container that is at a pressure of 0.75 atm and 300 K.
Learn more about number of moles at: brainly.com/question/1190311
