Molar mass of Al = 26.98
molar mass of Al2O3 = 101.96
36 / 26.98 = 1.3343 moles Al
set up a proportion : 1.3343 / 4 = x / 2 (let x = moles of Al2O3)
x = 0.66716 moles of Al2O3
0.66716 * 101.96 = 69.024 g of Al2O3
After 3 half life periods you would have 5 grams of krypton left because half of 40 is 20 half of 20 is 10 and half of 10 is 5
<u>Answer:</u> The formula of the compound formed between rubidium and fluorine is RbF
<u>Explanation:</u>
Ionic bond is defined as the bond which is formed by complete transfer of electrons from one atom to another atom.
The atom which looses the electron is known as electropositive atom and the atom which gains the electron is known as electronegative atom. This bond is usually formed between a metal and a non-metal.
Rubidium is the 37th element of the periodic table having electronic configuration of 
This will loose 1 electron to form
ion
Fluoride is the 9th element of the periodic table having electronic configuration of 
This will gain 1 electron to form
ion
To form
compound, 1 rubidium ion is needed to neutralize the charge on fluoride ion
The formation of the given compounds is shown in the image below.
So the molar mass of a Hydrogen molecule is 2. If you have 10 grams of Hydrogen molecules, you have 5 moles of Hydrogen molecules (10 moles of Hydrogen atoms). Avogadro's number is 6.0225x10^23. This means that one mole of a substance has that many particles.
Gravity when the mantle cools it becomes heavier and therfore sinks