1. which of the following is not an example of a polymer?

plastic

nylon

amino acid

polystyrene

2. a carbon atom is able to form four single covalent bonds because it

has four electrons and four protons.

has four valence electrons in its outermost energy level.

forms a polyatomic ion with a -4 charge.

forms a more stable isotope when it gains four more electrons.

3. an organic compound that contains a carbonyl group with a hydroxyl group attached to it is an example of a(n)

ester.

alcohol.

amine.

carboxylic acid.

4. all of the following release carbon into the atmosphere except the

combustion of fossil fuels.

cellular respiration of plants and animals.

burning of trees in deforestation.

sedimentation of dead organisms.

Answer 1 : Amino Acids

Amino acid are monomers which forms protein as the polymer. They are monomers which join together by peptide bond to form long polypeptide sequences or proteins.

Answer 2: Has four valence electrons in its outermost energy level.

This property of carbon helps it to form bonds with other elements to form compounds. it is known as catenation property of carbon to form bonds.

Answer 3: Carboxylic acid

An organic compound having a carbonyl group along with a hydroxyl group also is called as carboxylic acid. Example: CH3COOH (acetic acid).

Answer 4: Sedimentation of dead organism.

The processes that release carbon into atmosphere include burning of fossil fuels and trees ,cellular respiration by organisms as all these processes release carbon dioxide into the environment.

The sedimentation of dead organism does not releases carbon dioxide into the atmosphere.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.