Basic Science T...

Which one of the following properties changes with valency? 

An atom of carbon has 6 protons. Its mass number is 12. How many neutrons are present in an atom of carbon ?

Consider the following statements 
1) The neutron was discovered in 1932 by bombarding beryllium with $$ \alpha$$-rays.
2) The electron and proton have equal but opposite electron charges.
3) The neutron is not charged.
Which of the statements given above are correct ?

Which one of the following is also called stranger gas __________.

Which of the following statements is correct ?

How many cubic centimetres $$(cm^3)$$ are in a cubic metre $$(m^3)$$? 

Consider the following statements 
1) the positive charge is essentially immovable because it contains practically all the mass of the atom.
2) Atom is the smallest indivisible particles of an element which takes part in a chemical reaction
Which of the above is / are correct ?

Consider the following statements 
1) Clusters of atoms that act as an ion are called polyatomic ions.
2) In ionic compounds , the charge on each ion is used to determined the chemical formula of the compound.
Which of the statement(s) given above is / are correct ?

The most of the mass of the atom can be found in_______.

Human wants are ___________.