Answer: a) 
: Decomposition
b) 
: double displacement
c) 
: Synthesis (Combination)
d) 
: redox
Explanation:
Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.
A double displacement reaction is one in which exchange of ions take place.
Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.
Redox reaction is a type of chemical reaction in which oxidation and reduction takes place in one single reaction. The oxidation number of one element increases and the oxidation number of other element decreases.
Answer:
Exolaiend in explanation section
Explanation:
First of all, the automatic hammer is used to drive nails into tight spaces where where we can't get a sufficient striking force if we are to use a normal regular hammer in driving the nail.
So the nail to be driven is lifted out of rest(it's position). The energy here is gravitational potential energy.
Now, when it is driven into the tight spaces, the gravitational energy would be converted to kinetic energy due to the motion and speed involved.
Answer:
As nouns the difference between impression and imprint
is that impression is the indentation or depression made by the pressure of one object on or into another while imprint is an impression; the mark left behind by printing something.
I think the answer is chemical change
Answer:
A neutral particle made of an electron and hole
Explanation:
Exciton
It is the combination of an electron and a hole ( hole refers to the vacancy of an electron ) . And , as both the electron and the hole have the same charge but the polarity is opposite , the combination will lead to a neutral compound , i.e. , Exciton have no charge and so neutral .
It is free to move in the nonmetallic crystal and since it charge less , it is difficult to detect it directly .
