They are determined by the length of time it takes for light to travel from the Earth to the desired star
Explanation :
(a) 
This reaction is combustion reaction in which an oxygen react with a molecule to give its corresponding oxides ans water molecule.
(b) 
This reaction is a redox reaction or oxidation-reduction reaction in which sulfur get oxidized and oxygen get reduced.
(c) 
This reaction is a combination reaction in which the two reactants molecule combine to form a large molecule or product.
(d) 
This reaction is a decomposition reaction in which a large molecule or reactant decomposes to give two or more molecule or products.
(e) 
This reaction is a double displacement reaction in which the cation of two reactants molecule exchange their places to give two different products.
(f) 
This reaction is a combination reaction in which the two reactants combine to form a large molecule or product.
(g) 
This reaction is a double displacement reaction in which the cation of two reactants molecule exchange their places to give two different products.
(h) 
This reaction is combustion reaction in which a hydrocarbon react with an oxygen to give carbon dioxide and water as a products.
All organisms need water, vitamins, minerals, and salt together to balance things out.
Answer:
The timber companies removing all the trees from entire hillside when they are harvesting logs is a practice that could cause the following when it is time to plant in spring:
1. It could affect the quality of plant needed nutrients in the soil and beneficial microorganism population in the soil which could impact negatively the planting season.
2. Trees serves as protection of soil nutrients against wind erosions, so the soil nutrients would be affected.
The farmers tilling the soil means preparing the soil for a farming season as the following effect:
1. Helps control weed for the planting season.
2. This practice could further encourage soil erosion if not done well.
3. Tilling the soil could make leftover plants from the felling of trees mix well with the soil and also add nutrients to the soil when they decay.
Answer:
Answer is 'B' I think
Explanation:
Rutherford's Gold Foil Experiment proved the existence of a small massive center to atoms, which would later be known as the nucleus of an atom. Through previous experiments of shooting alpha particles, Rutherford knew they had considerable mass and speed.
