I am very confused, our teacher didn’t properly teach us this. How do you do it?

You multiply the 3 numbers together to get your volume, in this case it would be 4058.488 cm^3 (cm cubed)

so

V: 4058.488cm^3 ( round up to 4058.5 for convenience)

M: 27579

D: ?

So we divide mass by the volume to get density, which is

27579 / 4058.5 = ~6.79536 (can round up to 7 or 6.8)

This graph can help a lot, so maybe try and memorize it, hope I helped.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

b) nuclear ive learned that in a pedtrodic table