Answer:
18 * 10^19 atoms
Explanation:
We must first convert 57.8 mg to grams.
If 1000 mg = 1g
57.8 mg = 57.8/1000 = 57.8 * 10^-3 g
Now;
If 1 gold atom has a mass of 3.27X10^-22 grams
x gold atoms have a mass of 57.8 * 10^-3 g
x = 57.8 * 10^-3 g/3.27X10^-22 g
x = 18 * 10^19 atoms
On temperature 25°C (298,15K) and pressure of 1 atm each gas has same amount of substance:
n(gas) = p·V ÷ R·T = 1 atm · 20L ÷ <span>0,082 L</span>·<span>atm/K</span>·<span>mol </span>· 298,15 K
n(gas) = 0,82 mol.
1) m(He) = 0,82 mol · 4 g/mol = 3,28 g.
d(He) = 10 g + 3,28 g ÷ 20 L = 0,664 g/L.
2) m(Ne) = 0,82 mol · 20,17 g/mol = 16,53 g.
d(Ne) = 26,53 g ÷ 20 L = 1,27 g/L.
3) m(CO) = 0,82 mol ·28 g/mol = 22,96 g.
d(CO) = 32,96 g ÷ 20L = 1,648 g/L.
4) m(NO) = 0,82 mol ·30 g/mol = 24,6 g.
d(NO) = 34,6 g ÷ 20 L = 1,73 g/L.
Answer:
One is hands on and one is watching
Explanation:
I just know my science
Answer:
Substances 1 and 2
Explanation:
an element only has 1 kind of atoms :3