8. A. Density is independent of size (an intensive property).
9. B. The highest density is 1786 g/20cm^3, or 89.3 g/cm^3. The least is 512 g/20cm^3, or 25.6 g/cm^3. Therefore, the difference is 89.3 - 25.6, or 63.7 g/cm^3.
10. C. A bottle filled with air weighs less than one filled with marshmallows, because air is less dense than marshmallows.
11. D. The number represents the number of protons in the nucleus of the atom, as well as the atomic number of the element.
12. C. The number represents the atomic mass of the element, which is determined based on the relative abundance of each form of the element.
Acid Rain is formed when chemicals in the air get into rain and up the acidity levels!!!!!!
Hope this helps guys!
Answer:
The number of carbon atoms in the container is 1.806 × 10²⁴ or the container contains 1.806 × 10²⁴ atoms of carbon
Explanation:
By Avogadro's number, 1 mole of a substance contains 6.02 × 10²³ particles of the substance
Here we have 0.45 mole of CO₂ contains
0.45 × 6.02 × 10²³ particles of CO₂ that is 2.709 × 10²³ particles of CO₂ or equivalent to 2.709 × 10²³ atoms of Carbon
Similarly, 2.55 moles of CaC₂ contains 2.55 × 6.02 × 10²³ particles of CaC₂ or 1.5351 × 10²⁴ atoms of Carbon
The total number of carbon atoms is therefore;
2.709 × 10²³ + 1.5351 × 10²⁴ = 1.806 × 10²⁴ atoms of carbon.
Answer: 6.1 g
Explanation:
between Mg and MgO theres a 1;1 MOLE RATIO
here's the balanced equation
2Mg + O2 ==> 2MgO
24g of magnesium is approximately 1 mole of magnesium so it produces 40 g of mgo which is also 1 mole of mgo thus 10/40 =0.25 moles of MgO so 0.25 moles of magnesium would be needed which is approximately 6.1 g
