Answer:
atomic number
Explanation:
atomic number is the number of protons
Isn't a chemical change like something that's not a physical change or physically changed but is something that uses natural chemicals? that's my guess sorry if it's wrong I think I'm wrong though
Answer: the percent composition of carbon in heptane is 83.9%
Explanation:
<u>1) Atomic masses of the atoms:</u>
<u>2) Molar mass of heptane:</u>
- C₇H₁₆: 7 × 12.01 g/mol + 16×1.008 g/mol = 100.2 g/mol
<u>3) Mass of carbon in one mole of heptane:</u>
- C₇: 7 × 12.01 g/mol = 84.07 g/mol
<u>3) Percent composition of carbon:</u>
- % = (mass in grams of C) / (mass in grams of C₇H₁₆) × 100 =
= (84.07 g/ 100.2 g) × 100 = 83.9% ← answer
Answer:
Option A.
Lower air pressure results in a lower boiling point
Explanation:
This is because in an open system, the lower the pressure the lesser the energy that will be required for boiling point. The is little or no collision of air molecules with the surface of the liquid
But if there is increase in pressure, more energy will be required to get to boiling point because there will be strong collision between air molecules and surface of the liquid.
