The conservation of matter can be demonstrated by using chemical equations. Which chemical equation demonstrates the conservation of matter? A 2Sn + 4HNO3 → SnO2 + 4NO2 + H2O
B l2 + 5Cl2 + 6H2O + 2HIO3 + 10HCI
с Cl + 4Na + 4NaCl
D 4P + 5HNO3 → 5NO + 3H3PO4​

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

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

lol for the pointsss

you need to have a picture of the atom that way we can answer it