Answer:
Force of attraction = 35.96
N
Explanation:
Given: charge on anion = -2
Charge on cation = +2
Distance = 1 nm =
m
To calculate: Force of attraction.
Solution: The force of attraction is calculated by using equation,
---(1)
where, q represents the charge and the subscripts 1 and 2 represents cation and anion.
k = 
F = force of attraction
r = distance between ions.
Substituting all the values in the equation (1) the equation becomes

Force of attraction = 35.96
N
A.atomic mass(a)=16
atomic mass(b)=18
b.a and b are isotopes
c.(a)=2,6
(b)=2,6
The distance that jet covered in 10 min is 125 Km
calculation
distance = speed x time
speed=750 km/h
time= 10/60hrs
=750 x10/60=125 Km
Answer:
(iv) (A) is false, but (R) is true.
Explanation:
It is not true that carbon has a strong tendency to either lose or gain electrons to attain noble gas configuration. Carbon is a member of group 14, it is the first member of the group and carbon is purely a non metal. Only metals metals can loose electrons to attain the noble gas configuration. Moreover, carbon does not participate in ionic bonding so it does not gain electrons to attain the noble gas configuration.
However, carbon participates in covalent bonding where it is covalently bonded to four other chemical species using its four outermost electrons. Carbon forms covalent bonds in which four electrons are shared with other chemical species.
Answer:
I think it would be:
NaCO3 (s)-->Na2O (s) + CO2 (g)