Topic 2: Chem Basics

Question 1

Which elements are found in the highest abundance in humans?

Answer 1

Nitrogen
Oxygen
Hydrogen
Carbon

Question 2

Describe properties of protons, neutrons, and electrons and their arrangement within an atom.

Answer 2

Protons: Positively Charged
Neutrons: Neutral (No Charge)
Electrons: Negatively Charged

Protons and Neutrons make up the atoms nucleus. Electrons surround the nucleus.

Question 3

Choose an element and determine the number of protons, electrons, and neutrons.

Answer 3

Element: Chlorine
Protons (Atomic #): 17
Electrons (P=E, only in neutral elements): 17
Neutrons(P+N=Mass #): 18

Question 4

What is an isotope?

Answer 4

An isotope is different forms of the same element with the same number of protons but a different number of neutrons.

Question 5

How is the half-life of an isotope defined?

Answer 5

Half life is the time it takes for half of the original concentration of an isotope to decay back to its more stable form.

Question 6

What are some uses of radioisotopes in biology?

Answer 6

Radioisotopes are isotopes that are in an unstable state where the combination of neutrons and protons are unstable. They begin to emit radiation to attain a more stable atomic configuration.

Radioisotopes can help in tracing metabolic pathways.

Question 7

Choose an element and determine the electron configuration.

Answer 7

Electron Shells: s,p,d,f
S- 2 electrons
P-6 electrons
D- 10 electrons
F 14 electrons

Fluorine: 1s^2 2s^2 2p^5

Question 8

Compare and contrast covalent and ionic bonds. Define anion and cation

Answer 8

Both Covalent and Ionic Bonds satisfy the octet rule.

Covalent Bonds are super strong. They share electron to form extrinsic pairs. More common in living organisms. We can have Polar or Non-polar bonds.

Ionic bonds form between ions with opposite electric charges held together. There number of electrons do not equal the number of protons.

Cations are positive ions that form by losing electrons.
Anions are negative ions formed by gaining electrons.

Question 9

What is the difference between a polar covalent bond and a non polar covalent bond?

Answer 9

Polar Covalent Bonds: Unequally share Electrons and are attracted more to the nucleus an s+ and s- charge develops.

Nonpolar Covalent Bonds: Form when two atoms of the same element or between different elements share electrons equally.

Question 10

Describe a hydrogen bond and be able to identify one in a diagram.

Answer 10

Hydrogen Bonds are weak bonds. They include and Oxygen and a Hydrogen. An s+ hydrogen bonds with a s- oxygen.