The correct option is C.
A Lewis dot diagram is a representation of the valence electron of an atom, which uses dot around the symbol of the atom. Chlorine has seven electrons in its outermost shell, these seven electrons are arranged in form of dot around the atom of chlorine. If you count the number of dot given in option C, you will notice that they are seven.
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: amu
Explanation: it stands for atomic mass unit and it is the measurement that’s used to measure the mass of atoms
Answer:
B) the chemicals are gaining energy from the surroundings.
Explanation:
The positive sign of the energy difference in a chemical reaction would indicate that the chemicals are gaining energy from the surroundings. This is what happens in an endothermic reaction.
In an endothermic reaction, heat is absorbed from the surroundings hence the surrounding becomes colder at the end of the changes.
- Here the energy change is assigned a positive value.
- This is because the heat energy level of the final state is higher than that of the initial state.
- So, the difference gives a positive value.
salt is not because it gets u dehydrated