The volume of the nucleus of a carbon atom is about 9.9 10⁻³⁹. the molar mass of carbon is 12.00 g mol⁻¹. what is the density of the carbon nucleus?

Density is defined as the ratio of mass to the volume.

       (1)

Since, molar mass of carbon is given i.e. , determine the mass of carbon, we get

1 amu = 1 g/mol

1 amu =

Mass of carbon =

=

=  

Now, put the value of mass and volume in formula (1)

Density of carbon nucleus =    

=

=

Hence, density of carbon nucleus =

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms