Can someone help me balance these equations

1. A2 + B2 => 2 AB

2. 2 A + 3 B => A2B3

3. 2 A + 3 B2 => 2 AB3

4. A2 + 2 B2 => 2 AB2

5. 2 A2 + 3 B2 => 2 A2B3

Explanation: So to make the equations balance we will put numerical coefficients on each variable so that the total number of atoms will be equal on each side.

For number 1 we will put 2 on AB to balance the reactant. For number 2, we will write 2 on A and 3 in B in the reactant side. For number 3, write 2 on A and 3 on B2 in the reactant and 2 on AB3 in the product side. For number 4, the coeffecients are 1:2:2 and lastly on number 5 the coeffencients are 2:3:2.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.