Answer: pure substances.
Explanation:
The given substances are:
All what surrounds us, which has mass and occupies spaces, is matter. There are two kind of matter: pure substances and mixtures.
Pure substances have a uniform and constant composition. On the other hand, mixtures are combinations of two or more pure substances in any arbitratry ratio.
Pure substances may be elements or compounds. The elements are the substances conmposed by one only kind of atom. In the list of substances given, Li and O₂ are elements: all the atoms in Li are lithium, and all the atoms in O₂ are oxygen atoms.
Compounds are the chemical combination of two or more different kind of atoms. In the given list H₂O₂ and NaCl are compounds. As you see, H₂O₂ contains atoms of hydrogen and oxygen, chemically bonded, in a fixed ratio (2 atoms of hydrogen by 2 atoms of oxygen). And NaCl has atoms of Na (sodium) and Cl (chlorine), chemicaly bonded, in a fixed ratio (1:1).
There are only 118 known elements and you can find them in any modern periodic table. Therer are virtually infinitely many compounds since many different combinations of the elements can be attained.
Elements and compounds have in common that they are classified as pure substances.
<h2>Balance Chemical Equation</h2>
1. N2 + 3 H2 = 2 NH3
2. 2 KCIO3 = 2 KCI + 3 O2
3. 2 NaCI + F2 = 2 CI + 2 NaF
4. 2 H2 + O2 = 2 H2O
5. Pb(OH)2 + 2 HCl = 2 H2O + PbCl2
6. 2 AlBr3 + 3 K2SO4 = 6 KBr + Al2(SO4)3
7. CH4 + 2 O2 = CO2 + 2 H2O
8. C3H8 + 5 O2 = 3 CO2 + 4 H2O
9. 2 C8H18 + 25 O2 = 16 CO2 + 18 H2O
10. FeCl3 + 3 NaOH = Fe(OH)3 + 3 NaCl
11. 4 P + 5 O2 = 2 P2O5
12. 2 Na + 2 H2O = 2 NaOH + H2
13. 2 Ag2O = 4 Ag + O2
14. S8 + 12 O2 = 8 SO3
15. 6 CO2 + 6 H2O = C6H12O6 + 6 O2
16. 2 K + MgBr2 = 2 KBr + Mg
17. 2 HCl + CaCO3 = CaCl2 + H2O + CO2
18. HNO3 + NaHCO3 = NaNO3 + H2O + CO2 - already balanced
19. 2 H2O + O2 = 2 H2O2
20. 2 NaNO3 + H2SO4 = Na2SO4 + 2 HNO3
If it goes from a volume of x, then when the volume is doubled it will go to a volume of 2x. If you meant what happens to the pressure, then the pressure halves as volume doubles due to Boyle's law.
To find the atomic mass of chlorine, the atomic mass of each isotope is multiplied by the relative abundance (the percent abundance in decimal form) and then the individual masses are added together. The atomic mass of chlorine is 35.45 amu.
<span>First we can calculate the area of the rectangular lawn using the formula:
Area = Width x Length = 21 ft x 20 ft = 420 square feet
And the total number of snow flakes per minute on the entire lawn is:
(1350 snowflakes per minute per square foot) x (420 square feet) = 567,000 snowflakes per minute
In one hour (or 60 minutes) we get a total of:
(567,000 snowflakes per minute) x (60 minutes / 1 hour) = 34,020,000 snowflakes
The total mass of which would be:
34,020,000 snowflakes x 1.60 mg = 54,432,000 mg = 54.432 kg (as 1 kg = 1,000,000 mg).
So 54.432 kg of snow accumulates every hour on the lawn.</span>
