Answer:
causes a substance to change from a liquid to a solid.
Explanation:
It usually leads to Global warming .
Gases from a dead star gather and contract statement describes the formation of a nebula.
<u>Option: D</u>
<u>Explanation:</u>
- A nebula is a massive cloud of spatially dust and gas. Many nebulae derive from the gas and dust pushed out by a dying star's eruption, like a supernova. Other nebulae are environments where the formation of new stars begins.
- Five forms of cloudy or nebulous celestial bodies are planetary nebulae, emission nebulae, transparent nebulae, supernova remnants and dark nebulae.
- The He and H are predominantly responsible for dust and gases, which are widespread but gravity can begin to pull around each other clusters of dust and gas gradually.
- As these clusters grow bigger and bigger, their gravity becomes better and better. The clump of dusts and gases finally becomes so heavy that it drops from its own gravity.
Answer:
very reactive
Explanation:
The alkenes and alkynes are very reactive organic compound at their double and triple bonds participating in an extensive range of reactions which can be nucleophilc, addition , free radical reactions just to mention a few.
The reason for this reactivity is the high density of electrons due to the double and triple bonds responsible for the "unsaturation"
Answer:
Chlorination is a process which involves adding of chlorine to water but the chlorinating product which does not necessarily have to be pure chlorine