Answer:
i belive its c
Explanation:
Atoms of group 18 elements have eight valence electrons (or two in the case of helium). These elements already have a full outer energy level, so they are very stable. As a result, they rarely if ever react with other elements. Therefore, it is very reactive and gives up electrons in chemical reactions.
Answer:
Water moving across the earth in streams and rivers pushes along soil and breaks down pieces of rock in a process called erosion. The moving water carries away rock and soil from some areas and deposits them in other areas, creating new landforms or changing the course of a stream or river.
Explanation:
Answer:
d. Pressure
Explanation:
Pressure is not a factor which affect rates of reaction.
However, surface area, temperature, and concentration are factors that affect rates of reaction.
Answer : The metal used was iron (the specific heat capacity is 
).
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of metal = ?
= specific heat of water = 
= mass of metal = 47.1 g
= mass of water = 120 g
= final temperature of water = 
= initial temperature of metal = 
= initial temperature of water = 
Now put all the given values in the above formula, we get
Form the value of specific heat of metal, we conclude that the metal used in this was iron.
Therefore, the metal used was iron (the specific heat capacity is ).
The answer would be potassium nitrate.
