Answer:
is the density of solid calcium.
Explanation:
Formula used :

where,
= density
Z = number of atom in unit cell
M = atomic mass
= Avogadro's number
a = edge length of unit cell
We have:
r = 197 pm = 



M = 40 g/mol
Z = 4
On substituting all the given values , we will get the value of 'a'.


is the density of solid calcium.
Answer:
[Ar]3d^{10}4s^{2}4p^{6}
Explanation:
Electronic Configuration of Bromine : [Ar]3d^{10}4s^{2}4p^{5}
At oxidation state -1, electronic Configuration of Bromine : [Ar]3d^{10}4s^{2}4p^{6}
The solution for this problem is:
C6H5NH3Cl is a strong salt: C6H5NH3+ + Cl- C6H5NH3+ + H2O <-----> C6H5NH2 + H3O+
K = Kw/ Kb= 1.0 x 10^-14 / 3.8 x 10^-10= 2.6 x 10^-5
=2.6 x 10^-5 = x^2 / 0.240-x
x = [H3O+] = 0.00251 M
pH = 2.60 is the concentration
Answer:
Magnetic: Magnet being pulled to a metal surface- non- contact force
Friction: skateboard slowing down on a rough surface- contact force
Gravity: Ball falling to the ground - non-contact force
Electrical: Charged balloon pulling up on arm hair - non- contact force
Tension (pull): people playing tug-of-war - contact force
Applied (push): a person pushing a toy car - contact force
Air resistance: wind pushing on the sail of a sailboat - contact force
Spring: springs being pushed together -contact force
Explanation:
A contact force is a type of force that can only act when two bodies touch other physically. Examples of this include a push or a pull.
A non-contact force is a type of force that can only act when two bodies do not touch other physically. Examples include; electric force, magnetic force, etc.