Answer:
B
Explanation:
This is the First Law of Thermodynamics which states that energy cannot be created or destroyed.
Answer:
The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons. ... The value of the radius may depend on the atom's state and context.
Explanation:
There are 3 Na, 3 O, and 3 H since you distribute the coefficient 3 to all atoms. So, if you add them up, there are 9 atoms in that compound. Hope that helps!
Answer:
It depends what the compound is.
Explanation:
You need to use Avogadro's number (6.22*10^23) to convert the number of molecules of a compound to moles of the compound. From there, you can use the molar mass of the compound (grams per mole) to get the mass. You can get the molar mass by googling "molar mass of [compound]" or calculate it yourself using the periodic table.
So: 8.2*10^11 molecules of the compound * (1 mole of the compound/6.022*10^23 molecules of the compound) * (# of grams/1 mole of the compound)