Carbon atom has 4 valence electron and can form 4 bonds with carbon and other atoms and it can also form single, double and triple bond with other carbon atoms.
So, the statement is false.
A Diatom is under the phylum of Chrysophyta with the following characteristics:
1) Unicellular but often colonial
2) manufactures the carbohydrate chrysolaminarin
3) has unique double -shells of opaline silica
4) contains chlorophylls a and c
They are abundant in sea and fresh water where they serve as producers.
Diatoms are protists that have glass walls. Just like plants, they carry out cytokinesis. They are photosynthesizers with hard shells of silica. An example of a Diatom is Diatoma.
Diatoms are divided into two major groups, one with radial symmetry and the other with bilateral symmetry.
I think it would be option 4?
Density of maple syrup = 1.325 g/ml
1000 ml contains 1325 g of maple syrup
In 100 g of maple syrup - 67 mg of Ca ions
Therefore in 1325 g of maple syrup - 67 mg /100g * 1325 g
= 887.75 mg of Ca
this means in 1000 ml - 887.75 mg of Ca
molar mass of Ca - 40 g/mol
therefore number of moles in 1000 ml - 0.88775 g /40 g/mol
molarity of Ca - 0.022 mol/dm³
The coins in 1991 had more copper in them compared to the coins today. So, that is why it worth 3.3p.