Answer:
Silicon, Si forms covalent-network solids.
Explanation:
Silicon, Boron and Carbon are the elements that form covalent networks solids: solid materials whose units consists of chains or networks of atoms or molecules covalently bonded together. Silicon, Si has a similar structure to carbon, but not the exact hardness because Si-Si bonds are not as strong as carbon-carbon bonds.
An example of Si covalent compound is silicon dioxide.
Egyptians started doing maths first
Answer:
See the image below
Explanation:
To draw a Lewis structure of a molecule, you place the least electronegative atom (Xe) as the central atom, with the more electronegative atoms (O) surrounding it.
Then you distribute the electrons around the atoms, giving every one an octet and placing any extra electrons on the central atom.
This procedure gives you four possible Lewis structures, so the actual structure is a resonance hybrid of them all.
Structure D has no formal charges, so it is the major contributor.
Answer:
A and B plz mark brainliest
Explanation:
Chemical equilibrium is a condition where the rate of product made is same as the rate of reactant made. Since the reaction to the left is same as the reaction to the right, so the amount of reactant and product will not be changed (doesn't mean that the amount is same, it just won't increase or decrease).
It's called equilibrium since there will be no change in their amount.