A compound
its refers to a substance formed when two or more types of atoms bond chemically
Answer:
The third line
Explanation:
The first one us wrong because they're not all found inside,electron is outside.
The second one is wrong as I explained previously.
Lastly the fourth line is wrong because protons are found in the nucleus.
<span>The rate of crystallizing is equivalent to the rate of dissolving.</span>
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
.