An ionic compound is made up of two or more metals and non-metals
A covalent compound is made up of two or more non-metals.
Therefore calcium (non-metal) and chlorine(non-metal) make up a covalent compound
A chemical reaction is when atoms/molecules are taken apart and rearranged to create something new. So I think the answer is B
The carbon group has 4 valence electrons
Answer: The structure of
1-Butyne is shown below and it contains;
Nine Sigma Bonds Two Pi Bonds
Explanation:
In given structure the sigma bonds are highlighted with blue colour and pi bonds are highlighted by Black colour and indicated by red arrows.
Remember the very first covalent bond between two atoms is always the sigma bond. After formation of sigma bond if further p orbitals with unpaired electrons are available they will form pi bond, or two pi bonds as in given scenario.