Questions

The given statement that a calorie is another term for carbohydrate is False.

Carbohydrates are one of the main types of nutrients, and are most important source of energy.

Where as Calorie is a measurement of how much heat energy is generated by the body processing food.

Your digestive system changes carbohydrates into glucose(blood sugar). Your body uses this sugar for energy. 

The Length of the Day is determined in Astronomical Units.

The length of a day corresponds to the time the Earth takes to turn around on its axis, which is approximately 24 hours. But it's not exactly 24 hours. 

This phenomenon is due to tides raised by the Moon which slow Earth's rotation. Because of the way the second is defined, the mean length of a day is now about 86 400.002 seconds, and is increasing by about 1.7 milliseconds per century.

The letter 'X' resembles the same as the tool AXE in sounding.

Hence, the alphabet X is a tool.