Burning magnesium gives us magnesium oxide. this is an example of a reaction. is the common element involved with all chemical reactions of this kind. blank 1. combustion. decomposition. replacement. synthesis. blank 2. carbon. hydrogen. magnesium. oxygen.

its {Combustion and Oxygen}

Explanation: combustion means to burn something and as we all know you need oxygen for anything to burn or catch fire

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

the product of the pressure and volume is also constant