2,8,1
It's in group 1, so its outershell only has 1 electron, and the other shells are completely filled, so 2 then 8. :)
The number of protons in an atom is equal the atomic number (= 50)
The sum of the Neutrons and Protons is the Atomic Mass (=125)
Neutrons + Protons=125
Plug in for the protons (50)
Neutrons +(50)=125
Then, once solved, we have Neutrons = 75
Assuming the atom is NOT an ion, the amount of electrons is equal to the number of protons. (protons=electrons=50=50)
Therefore:
There are 50 electrons, 50 protons, and 75 electrons.
Answer:
Mass = 0.158 g
Explanation:
Formula used,
P V = n R T
Or,
n = P V / R T
Putting values,
n = 0.948 atm . 0.025 L / 0.0821 L.atm.K⁻¹.mol⁻¹ . 291.45
n = 0.00099 mol
Note: we have changed pressure from mmHg to atm, volume from mL to L and temperature from C to K)
Also,
Mass = n . Molecular Mass
Mass = 0.00099 mol × 159.808 g/mol
Mass = 0.158 g
Positive because it keeps going ok
