Answer:
4 and 6
Explanation:
Period 4 has 18 elements and so does period 6.
Answer: 1.27 bar
Explanation:
1 atm = 1.01325 bar
1.25 atm = Z (let Z be the unknown value)
To get the value of Z, cross multiply
Z x 1 atm = 1.25 atm x 1.01325 bar
1 atm•Z = 1.2665625 atm•bar
To get the value of Z, divide both sides by 1 atm
1 atm•Z/1 atm = 1.2665625 atm•bar/1atm
Z = 1.2665625 bar
(Round up Z to the nearest hundredth as 1.27 bar)
Thus, 1.25 atm when coverted gives 1.27 bar
We have to get the relationship between metallic character and atomic radius.
Metallic character increases with increase in atomic radius and decrease with decrease of atomic radius.
If electrons from outermost shell of an element can be removed easily, that atom can be considered to have more metallic character.
With increase in atomic radius, nuclear force of attraction towards outermost shell electron decreases which facilitates the release of electron.
With decrease in atomic radius, nuclear force of attraction towards outermost shell electrons increases, so electrons are hold tightly to nucleus. Hence, removal of electron from outermost shell becomes difficult making the atom less metallic in nature.
Answer: The vapor pressure of water at 10°C will be less as compared with its vapor pressure at 50°C.
Explanation:
Vapor pressure of a liquid is defined as the pressure exerted by the vapors in equilibrium with the liquid/solution at a particular temperature.
As Kinetic energy is dependent on the absolute temperature of the gas.

where R = gas constant
T = temperature
On increase in temperature, the kinetic energy of the molecules increase and thus more liquid molecules can escape to form vapours and thus will exert more vapor pressure.
Thus the vapor pressure of water at 10°C will be less as compared with its vapor pressure at 50°C.