<u>Answer:</u> The electronic configuration of gallium is written below and number of valence electrons is 3.
<u>Explanation:</u>
Electronic configuration is defined as the representation of electrons around the nucleus of an atom.
Number of electrons in an atom is determined by the atomic number of that atom.
Valence electrons are defined as the electrons present in the outermost shell of an atom.
We are given:
An element Gallium having atomic number as 31.
Number of electrons = 31
Electronic configuration of Gallium is: 
This element has 3 electrons in its outermost shell. So, the number of valence electrons is 3
Hence, the electronic configuration of gallium is written below and number of valence electrons is 3.
<h2>Answer:</h2>
It means the waves collides and constructive interference occurred.
<h3>Explanation:</h3>
If the two waves coming from the opposite direction collide with each other, there are two way of their interference.
- Constructive interference: An interference which results in the increase in energy. And it is when crust of a wave comes on the crust of second wave.
- Destructive interference: An interference which results in decrease in energy of the resulting wave and colliding waves cancel the result of each other.
Hence in experiment there will be constructive interference.
Answer:
Noble gases have a complete valence electron shell making them stable and nonreactive.
Explanation:
Answer:
a number assigned to an element in chemical combination which represents the number of electrons lost (or gained, if the number is negative), by an atom of that element in the compound
Explanation:
sodium, magnesium, iron is zero.
Answer:
Explanation:
There are no molecules in NaCl, because it consists only of ions.
However, we can calculate the number of formula units (FU) of NaCl.
Step 1. Calculate the moles of NaCl
Step 2. Convert moles to formula units
There are 
in 3.6 g of NaCl.
