V1 = 30 mL
P1 = 760 torr
P2 = 1520 torr
V2 = ?
applying Boyle's Law
P1*V1 = P2*V2
760 torr * 30 mL = 1520 torr * V2
V2 = 760 torr * 30 mL / 1520 torr
( C ) is correct
 
        
             
        
        
        
The scientist thought that the
atom was the smallest particle in the universe is John Dalton. He established
the atomic theory which consists of five; elements are made of extremely small
particles called atoms, atoms of different element have different sizes, mass
and physic – chemical properties, atoms cannot be divided further, destroyed or
created, atoms can combine to form compounds and in chemical reaction, atoms
can be combined, separated or rearranged. 
 
        
                    
             
        
        
        

28%
Explanation:
mass of solute(KBr) = 3.73g
mass of solvent(H2O) = 131g
mass of solution = mass of solute + mass of solvent
= 3.73 + 131
= 134.73g

 
        
             
        
        
        
Answer:
1. Ions are either negatively or positively charged species in which the number of electrons and protons are not equal. 
2. The chemical bond that arises due to the sharing of electrons is termed a covalent bond. 
3. The positively charged ions are called cations, which comprise more protons than electrons. 
4. An example of a polyatomic anion is the hydroxide anion. 
5. The system of assigning an unambiguous name to a compound is called nomenclature.
 
        
             
        
        
        
False, pepsin and hydrochloric acid