Answer:
Nucleus
Explanation: it is the center of the atom, and contains protons and nuetrons
Answer: 118.5 grams
Explanation:
Molarity is defined as the number of moles of solute dissolved per liter of the solution.

where,
n= moles of solute
= volume of solution in ml = 500 ml

moles = 0.75
moles of solute =
0.75 =
mass of
= 118.5 grams
Thus mass of
needed to prepare 500 mL of this solution iis 118.5 grams
Answer : The value of 'R' is 
Solution : Given,
At STP conditions,
Pressure = 1 atm
Temperature = 273 K
Number of moles = 1 mole
Volume = 22.4 L
Formula used : 
where,
R = Gas constant
P = pressure of gas
T = temperature of gas
V = volume of gas
n = number of moles of gas
Now put all the given values in this formula, we get the values of 'R'.


Therefore, the value of 'R' is
.
<span>D the temperature decreases and the pressure increases</span>