Answer:
Atoms were impenetrably hard, meaning they could not be divided. In Greek, the prefix "a" means "not" and the word "tomos" means cut. Our word atom therefore comes from atomos, a Greek word meaning uncuttable.
the san andreas fault is the correct answer
Answer:
CO.
Explanation:
Assuming the given percentages are by mass, we can solve this problem via imagining we have <em>100 g of the compound</em>, if that were the case we would have:
Now we <u>convert those masses into moles</u>, using the<em> elements' respective molar masses</em>:
- 42.9 g of C ÷ 12 g/mol = 3.57 mol C
- 57.1 g of O ÷ 16 g/mol = 3.58 mol O
As the number of C moles and O moles is roughly the same, the empirical formula for the compound is <em>CO</em>.
Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
