Answer : The pressure of the helium gas is, 1269.2 mmHg
Explanation :
To calculate the pressure of the gas we are using ideal gas equation:

where,
P = Pressure of
gas = ?
V = Volume of
gas = 210. mL = 0.210 L (1 L = 1000 mL)
n = number of moles
= 0.0130 mole
R = Gas constant = 
T = Temperature of
gas = 
Putting values in above equation, we get:


Conversion used : (1 atm = 760 mmHg)
Thus, the pressure of the helium gas is, 1269.2 mmHg
Answer:
The only nonmetal in group 14 is carbon.
Explanation:
Carbon molar mass=12
carbon mass in the above question =6
mole=number of atoms/6.02x10²³
6/12= number of atoms/6.02x10²³
number of atoms=1/2 x6.02x10²³
number of atoms= 6.02 x10²³/2
number of atoms=3.01x10²³
Answer:
Protons= Positive charge
neutrons= neutral charge
electrons= negative charge
Protons and neutrons make up nucleus
Electron travels around the nucleus
Explanation:
The rates of the forward and reverse reaction depends on the temperature on which the reaction will proceed, either endothermic of exothermic. it also depends of the concentration of the reactants and products. if the reaction is exothermic, so if the reaction temperature is increased then it will favor the forward reaction, then if the reaction is lowered then it will favor the reverse reaction