Answer:
The atoms on left side are larger than the atoms on the right side of the periodic table because those on the right have more proton's.
Explanation:
As we travel along a period in a periodic table then the atomic radii decreases
This is because as we travel along a period we have that the atomic number of the atoms increases which means the the number of proton's increased
But the electron's add to the same outer shell throughout the period , which means the effective nuclear charge increases which pulls the outer electrons toward's the nucleus and the size decreases.
Therefore the atoms on left side are larger than the atoms on the right side of the periodic table because those on the right have more proton's.
Answer : The correct option is, (b) 22.5 M
Explanation : Given,
Mass of calcium nitrate tetrahydrate = 266 g
Molar mass of calcium nitrate tetrahydrate = 236.15 g/mole
Volume of solution = 
Molarity : It is defined as the moles of solute present in one liter of solution.
Formula used :
Now put all the given values in this formula, we get:
As calcium nitrate tetrahydrate dissociate to give 1 mole of calcium ion, 2 moles of nitrate ion and 4 moles of water.
The concentration of nitrate ion = 
Thus, the concentration of nitrate ion is, 22.5 M
Answer: Anna stated that ionic compounds have high melting point and low boiling point. The error in the statement is that ionic compound have low boiling point, instead ionic compounds have high boiling point, because in an ionic compound, the force of attraction working between two ions is very strong and hence the bonds present are very strong, and a lot of energy is needed to break them
Hydrogen bonding is important because it is crucial to all life on Earth. Here are three reasons why hydrogen bonding is important. DNA has a double-helix structure because hydrogen bonds hold together the base pairs in the middle. Without hydrogen bonds, DNA would have to exist as a different structure.
Number of proton K=19
so, 42 - 19 =23
then the answer in 19 protons and 23 neutrons
