Yeah science is hard. Hopefully you do good in it :)
Explanation:
A chemical reaction is a reaction in which two or more species combine together to form a molecule with a new chemical composition.
In a chemical reaction, the reactants are written on left hand side pointing a forward arrow towards the products which are written on the right hand side.
For example, chemical reaction between hydrogen and oxygen will result in the formation of water. The reaction equation will be as follows.

Answer:
Velocity will be equal to 7.31 m/sec
Explanation:
We have given mass of the student m = 61 kg
Height of the water slide h = 12.3 m
Acceleration due to gravity 
Potential energy is equal to 
Work done due to friction = -5800 J
So energy remained = 7352.94-5800 = 1552.94 J
This energy will be equal to kinetic energy
So 


v = 7.13 m/sec
A relationship exists and the numbers cause one another can be said about two numbers that have either a positive or negative correlation
Option : C
<u>Explanation:</u>
When two numbers have positive correlation, they move in the same direction. If the first variable increases, the second one also increases and if one variable decreases the other one also decreases.If the two numbers have negative correlation, the two numbers move in opposite directions.
A relationship exists between two numbers and the number cause one another. A correlation means that changing one variable affects the other. Correlation among variables need not necessarily imply causation. Positive correlations are mostly used in Finance and stock markets.
Two or more elements that are chemically combined