1 mole ------------- 22.4 L ( at STP )
?? mole ---------- 12 L
12 x 1 / 22.4 => 0.5357 moles
hope this helps!
The number of protons, neutrons, and electrons in an atom can be determined from a set of simple rules. The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons.
Answer:
91.1835 nm
Explanation:
Given that the ionization energy of the oxygen molecule = 1314 kJ/mol
It means that
1 mole of oxygen molecules can be ionized by the energy = 1314 kJ = 1314000 J
1 mole of molecules contains 6.022 × 10²³ atoms
So,
6.022 × 10²³ atoms of oxygen molecules can be ionized by the energy = 1314000 J
1 atom require
of energy
Energy = 
Also
Where,
h is Plank's constant having value
c is the speed of light having value 
is the wavelength
So,
Also,
So, wavelength = 91.1835 nm
“Metal ions are typically smaller than their corresponding neutral atoms”
Answer) Smaller
Explanation:
If the density of the object is more than that of water, it will sink. Otherwise it will float. The density of water is 1 g/mL.
Substance 1,
Mass, m = 450 g, Volume, V = 90 mL
Density = mass/volume
So,

It will sink.
Substance 2,
Mass, m = 35 g, Volume, V = 70 mL
Density = mass/volume
So,

It will float.
Substance 3,
Mass, m = 24 g, Volume, V = 12 mL
Density = mass/volume
So,

It will sink.