A mixture of charcoal, sand, sugar, and water is a heterogeneous mixture. Sugar can easily dissolve in water. Slightly heating the mixture will ensure all of the sugar is dissolved in the water. The mixture then can be filtered to separate out sugar solution from sand and charcoal. The mixture of sand and charcoal is washed several times with water and filtered so that no traces of sugar solution remain in the mixture. To the mixture containing sand and charcoal, water is added. Charcoal being lighter floats on the surface of water, whereas sand being heavy sinks to the bottom. The charcoal floating can be removed manually. After all the charcoal is removed, the mixture of sand and water is again filtered and the sand collected on filter paper is dried. Therefore, by using the above process sand can be separated out from a mixture of charcoal, sand, sugar, and water.
Density is mass divided by volume. Therefore, volume is mass divided by density.

Answer:
Element X with atomic number 10 and atomic mass 21
Element Z with atomic number 10 and atomic mass 22
Explanation:
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- Isotopes of an element have the same electronic configuration.
- They share the same chemical properties
- They only differ in their masses.
So, Element X and Z with atomic number 10 which is their number of electrons are isotopes. Their mass number, 21 and 22 differs.
Answer:
Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions
Explanation:
C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O