Given: The number = 0.0069 that has to be expressed in scientific notation
Concept: When we express any number in scientific notation then we shall consider two points.
(i) If we shift the decimal point from left to right after first (non-zero) digit then we count the number of shifted place of decimal and write them in terms of the negative power of 10. For example, 0.004789 = 4.789 ×10⁻³
(ii) If we shift the decimal point from right to left after first (non-zero) digit from the left end then we count the number of shifted place and write then in terms of the positive power of 10. For example, 4789.24 = 4.78924 ×10⁺³ = 4.78924 ×10³ Now, we shall convert the given number 0.0069 in scientific notation
0.0069 = 6.9 ×10⁻³ because we have shifted the decimal from left to right for three places that is after digit 6.
Hence, the last option 6.9 ×10⁻³ will be the correct option.
In a cell, protein synthesis is the primary function of the ribosomes, found in both eukaryotic and prokaryotic cells.
A Ribosome is a cell organelle that makes protein. The location of the ribosome in a cell determine the kind of protein it makes. If the ribosome is attached to the endoplasmic reticulum, the proteins made are utilized both within and outside the cell. If the ribosome is in the cytoplasm, floating freely, then the kind of protein made will be utilized within the cell only.
A liquid requires enthalpy of vaporization to transform into vapor or gas at its boiling point. Here the element absorbs heat from surroundings or heat source.
This energy is used in breaking the forces of attraction among the atoms and molecules of the element. The molecules get separated to higher distances. The energy is converted in to the kinetic energy of the molecules in gaseous form and into the internal energy in terms of the temperature of the gas.
Explanation:
It is given that,
Total weight of the piston, W = F = 70 N
Area of the piston, 
Let P is the pressure exerted on the piston by the gas. The force per unit area is called the pressure exerted pressure of the gas. Mathematically, it is given by :
We know that the atmospheric pressure is given by :
So, the pressure is given by :
Hence, this is the required solution.
