Two substances cannot react with each other unless their constituent particles (molecules, atoms, or icons) come into contact if there is no contact the reaction rate will be ZERO
Answer:
The correct answer is option 2.
Explanation:
Colligative property is defined as property which depends upon only on the numbers of particles of solute dissolved in definite amount of solvent, It do not depend on the nature of the solute.
For example : NaCl solution with 0.4 molal will show same colligative properties as a that of the glucose solution with 0.04 molal concentration.
The following are the examples of colligative property:
1. Relative lowering of vapor pressure.
2. Osmotic pressure
3. Elevation in boiling points
4. Depression in freezing point
POPULATION SIZE DECREASE
Population size can increase, but it can also decrease.
We know that amount of resources available affects the population size.
Natural disasters such as floods,fires,volcanic eruptions, can also affect the population size.
Sometimes the population size will decrease so much that it threatens the entire species.
Answer: Mutations are important to the evolution of a species because is creates new DNA for a certain gene, creating a new allele.
Hope this helps!!! Good luck!!! ;)
<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.
