1s^2 2s^2 2p^6 for the Mg2+ ion.
Repeat trials multiple times
Answer:
the atomic number is 5
the atomic mass is 11
Explanation:
The atomic number is the amount of protons inside the nucleus, and this number also equals the amount of electrons. Since it shows you the nucleus and the electrons, all you need to do is count the protons (positive charge inside the nucleus) or count all the electrons (negative charge outside the nucleus, in the rings) and you should have your atomic number.
As for mass, all you need to do is count all the protons and neutrons inside the nucleus and add them up. Protons = 5, Neutrons = 6. (you add them since the equation for atomic mass is Atomic Mass = Protons + neutrons. This works every time)
5+6= 11, so your atomic mass is 11
I hope this helps :)
Answer:
0.5077 moles
Explanation:
Data Given:
Moles = n = <u>???</u>
Temperature = T = 300 K
Pressure = P = 380 mmHg = 0.50 atm
Volume = V = 25 L
Formula Used:
Let's assume that the hydrogen gas in balloon is acting as an Ideal gas, the according to Ideal Gas Equation,
P V = n R T
where; R = Universal Gas Constant = 0.082057 atm.L.mol⁻¹.K⁻¹
Solving Equation for n,
n = P V / RT
Putting Values,
n = (0.50 atm × 25 L) / (0.082057 atm.L.mol⁻¹.K⁻¹ × 300 K)
n = 0.5077 moles
The density of it would be 57. Do the math and apply the formula to it and you would get this answer.