Explanation:
As a neutral lithium atom contains 3 protons and its elemental charge is given as
. Hence, we will calculate its number of moles as follows.
Moles = 
= 
= 100 mol
According to mole concept, there are
atoms present in 1 mole. So, in 100 mol we will calculate the number of atoms as follows.
No. of atoms = 
=
atoms
Since, it is given that charge on 1 atom is as follows.

= 
Therefore, charge present on
atoms will be calculated as follows.

Thus, we can conclude that a positive charge of
is in 0.7 kg of lithium.
Answer: Option (b) is the correct answer.
Explanation:
According to the law of conservation of energy, it is known that energy can neither be created nor it can be destroyed.
But energy can be changed from one form to another.
Whereas entropy is the degree of randomness present within the molecules of a substance or object.
For example, gas molecules are able to move rapidly so, they have more entropy as compared to solid and liquid substances.
According to second law of thermodynamics, entropy of the system is always increasing.
Thus, we can conclude that "Conservation of energy" refers to the fact that energy cannot be created or destroyed but can be converted from one form to another.
Answer:
Heat transfer = Q = 62341.6 J
Explanation:
Given data:
Heat transfer = ?
Mass of water = 50.0 g
Initial temperature = 30.0°C
Final temperature = 55.0°C
Specific heat capacity of water = 4.184 J/g.K
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 55.0°C - 30.0°C
ΔT = 25°C (25+273= 298 K)
Q = 50.0 g × 4.184 J/g.K ×298 K
Q = 62341.6 J
<span>The elastic potential energy stored in the stretched rubber band changes to kinetic energy.</span>
Answer:
is capable of combining with oxygen to form iron oxide