Answer: Root nodules are associations between bacteria and plant roots responsible for nitrogen fixation.
Explanation:
- As nitrogen present in atmosphere cannot be used by plants directly.
- Nitrogen present in atmosphere is converted into nitrogen compounds by bacteria which is present in root nodules of a plant.
- These compounds of nitrogen are then used by plants for various functions.
Answer: 0.8541 grams of HCl will be required.
Explanation: Moles can be calculated by using the formula:
Given mass of 
= 0.610 g
Molar mass of = 78 g/mol
Number of moles of = 0.0078 moles
The reaction between and HCl is a type of neutralization reaction because here acid and base are reacting to form an salt and also releases water.
Chemical equation for the above reaction follows:
By Stoichiometry,
1 mole of reacts with 3 moles of HCl
So, 0.0078 moles of will react with 
= 0.0234 moles
Mass of HCl is calculated by using the mole formula, we get
Molar mass of HCl = 36.5 g/mol
Putting values in the equation, we get
Mass of HCl required will be = 0.8541 grams
<span>The molecular mass of sodium oxide (Na2O) is A. 61.97894. The molecular mass of a molecule (Mr) is the sum of atomic masses of its atoms (Ar). The molecular mass of sodium oxide is: Mr(Na2O) = 2 * Ar (Na) + Ar(O). From the periodic table, Ar(Na) = 22.989769 and Ar(O) = 15.9994. The molecular mass of sodium oxide is: Mr(Na2O) = 2 * 22.989769 + 15.9994 = 45.979538 + 15.9994 = 61.97894.</span>
The charge of the cadmium cation is +2
Animal cells are round, plant cells are circle (most of them) Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall.
