There are 9 oxygen atoms in 3Al2O3. Each formula unit of Al2O3 contains 3 oxygen atoms, so 3 formula units will have 9 oxygen atoms in total.
Aluminum oxide, Al2O3, is an ionic compound. There are no molecules in it.
There are 20 atoms and there are 6 Carbon atoms, 8 Hydrogen atoms, 6 Oxygen atoms.
Fumarate has four carbon atoms.
Br2 consists of two atoms of bromine.
There are 9 oxygen atoms in 3Al2O3. Each formula unit of Al2O3 contains 3 oxygen atoms, so 3 formula units will have 9 oxygen atoms in total.
The numbers at the beginning of a chemical equation indicate the stoichiometry or the relative amounts of each reactant and product in the reaction. In the example you provided, "3Al2O3" means that three molecules of aluminum oxide (Al2O3) are involved in the reaction.
Aluminum oxide, Al2O3, is an ionic compound. There are no molecules in it.
temperatures above 1100 °C kyanite decomposes into mullite and vitreous silica via the following reaction: 3(Al2O3·SiO2) → 3Al2O3·2SiO2 + SiO2
10
There are 20 atoms and there are 6 Carbon atoms, 8 Hydrogen atoms, 6 Oxygen atoms.
C8H16O8 has a total of 24 atoms (8 carbon atoms, 16 hydrogen atoms, and 8 oxygen atoms).
5 atoms
9 atoms
45 atoms
Five atoms
402 atoms