Answer:
An element is made of only one type of atom. (Oxygen or sulphur) A compound is two or more elements that are chemically combined. (Iron oxide or Carbon monoxide)
Explanation:
Answer:7.92 N
Explanation:
Given
mass of book 
coefficient of static friction 
coefficient of kinetic friction 
To move the book, one need to overcome the static friction
Static friction 



After overcoming the Static friction , Force needed to move the block is



Answer:

is the no. of electrons
Explanation:
Given:
- quantity of charge transferred,

<u>No. of electrons in the given amount of charge:</u>
As we have charge on one electron 
so,


is the no. of electrons
- Now if each water molecules donates one electron:
Then we require
molecules.
<u>Now the no. of moles in this many molecules:</u>

where
Avogadro No.


- We have molecular mass of water as M=18 g/mol.
<u>So, the mass of water in the obtained moles:</u>

where:
m = mass in gram


Answer:
Mass doesn't change.
Weight is measured based on gravitational pull.
Explanation:
The answer is C. 35m/s because there is no direction