Questions

Covalent bonds hold atoms together because the attraction between the positively charged nuclei and the negatively charged shared electrons is greater than the repulsions between the nuclei themselves.

Alcohol has many sensations and effects like dizziness, nausea and loss of concentration.

Milk is not a pure substance since it has so many constituents that can be separated physically.

Compounds are pure substances formed from elements unlike mixtures.

The freezing point of water and melting point is 0 °C or 32 °F. The temperature may be lower if supercooling occurs.

Trypanasoma is a protozoan animal. It lives as a parasite in the blood and later invades the cerebrospinal fluid to cause the sleeping sickness. This parasite is transmitted by the Tsetse fly.