Out of the five major mass extinction, one is Cretaceous-Tertiary extinction (K-T extinction). It happened 66 million years ago marked by the end of the Cretinous period.
<u>Answer:</u> The net ionic equation is written below.
<u>Explanation:</u>
Net ionic equation of any reaction does not include any spectator ions.
Spectator ions are defined as the ions which does not get involved in a chemical equation. They are found on both the sides of the chemical reaction when it is present in ionic form.
The chemical equation for the reaction of sodium carbonate and nickel (II) chloride is given as:

Ionic form of the above equation follows:

As, sodium and chloride ions are present on both the sides of the reaction. Thus, it will not be present in the net ionic equation and are spectator ions.
The net ionic equation for the above reaction follows:

Hence, the net ionic equation is written above.
The reaction between K₂SO₄(aq) and SrI₂(aq) produces KI(aq) and SrSO₄(s) as products.
The reaction is
K₂SO₄(aq) + SrI₂(aq) → KI(aq)+ SrSO₄(s)
To balance the equation both side of the reaction should have same number of atoms in each element.
Right hand side of the reaction has 1 K, 1 I, 1 Sr, 1 S and 4 O atoms while 2 K, 2 I, 1 Sr,1 S and 4 O present in left hand side of the reaction.
Hence, number of I atoms and number of K atoms are not balanced.
To balance the K atoms we should add 2 before KI. Then I atoms will be 2 at the right hand side.
Hence, the balanced reaction equation is
K₂SO₄(aq) + SrI₂(aq) → 2KI(aq)+ SrSO₄(s)
The net cell reaction is: 2Al(s) + 2Br2(l) → 4Br(s) + 2Al2O3(s)
What is a net cell reaction?
A net cell reaction is the overall chemical reaction that occurs during a redox reaction in a cell. It is the sum of all of the individual chemical reactions that take place in the cell and is usually written as an equation with the reactants on the left-hand side and the products on the right-hand side.
What is a chemical reaction?
A chemical reaction is a process in which two or more substances interact to form new substances with different chemical properties. Chemical reactions involve the breaking and forming of chemical bonds, releasing or absorbing energy, and can be either exothermic (releasing energy) or endothermic (absorbing energy).
To know more about chemical reactions,
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