When two magnets are brought near each other, like poles repel; opposite poles attract. When a magnet is brought near a piece of iron, the iron also gets attracted to the magnet, and it acquires the same ability to attract other pieces of iron.
The first reaction is a synthesis reaction (A+B -> AB)
The answer is 3). This is because elements are the simplest form of a substance, and cannot be broken down any further. Compounds on the other hand are much more complex than elements and can be broken down INTO elements.
For example, Na, sodium, is an element and cannot be broken down further. H2O, water, is a compound and can be broken down into Hydrogen and Oxygen.
The reactants in the neutralization reaction are an acid and a base while the products are a salt and water.
Answer:

Explanation:
= Initial pressure = 931 torr = 
= Final pressure = 113 kPa
= Initial volume = 350 mL
= Final volume
From the Boyle's law we have

The volume the gas would occupy is
.