2.1 Chem Review

Question 1

Define Isotopes

Answer 1

different forms of the same atom that vary in # of neutrons but have the same number of protons

Question 2

How is carbon dating done?

Answer 2

By comparing the ratio of 14C and 12C in the atmosphere and in the fossil, therefore the amount of the isotope that did not decap can be determined

Question 2

What is half-life?

Answer 2

half of the original concentration will go back to this form ( half of the original concentration will go back to this form after 5730 years later)

Question 3

How can we use carbon dating in biology?

Answer 3

By studying the age of fossiles of extinct organism can help us understand how organisms have evolved

Question 4

Define chemical reactivity

Answer 4

the ability to combine and to chemically bond with each other. Based on the # and spatial distribution of an atom’s electrons

Question 5

Law of conservation

Answer 5

mass is not destroyed or created

Question 6

What is a reversible reaction?

Answer 6

some products can be turned back into reactants

Question 7

what is equilibrium?

Answer 7

back and forth balancing until a relative balance occurs

Question 8

What law is used maintain the homeostasis of blood

Answer 8

Law of mass action; carbonic acid leaving the body as carbon dioxide gas (exhalation) leaves which drives the reaction to right

Question 9

What are cations and anions?

Answer 9

Cations- positively charged ions
Anions- negative charged atoms

Question 10

What are ionic bonds?

Answer 10

Forms between ions of opposite charges

Question 11

What are electrolytes?

Answer 11

ions needed for nerve impulse conduction, muslce contractions and water balance

Question 12

What are some examples of electrolytes?>

Answer 12

sodium, potassium and calcium

Question 13

What are covalent bonds

Answer 13

Bonds that share electrons and are very strong due to their ability to make double and triple bonds

Question 14

Why can’t nitrogen be used in the atmosphere?

Answer 14

Due to their triple bond which doesn’t allow it to break

Question 15

What are polar covalent bonds?

Answer 15

electrons unequally shared which creates partially charged ions

Question 16

Why is one electron more attracted to one molecule compared to another one?

Answer 16

Due to its stong electronegativity (attraction)

Question 17

What are nonpolar covalent bonds

Answer 17

share electrons equally

Question 18

What are hydrogen bonds?

Answer 18

weak between slighlty positive hydrogen atoms and slightly negative hydrogen atoms. commonly occurs between water molecules and zips together the DNA double helix

Question 19

What are Van der Waals interaction

Answer 19

occur between any two or more molecules that are close to each other and dependent on slight fluctuations of electron densities; contributes to the structure of protein

Question 20

Electronegativity chart to show polarity

Answer 20

0- nonpolar covalent
0.5- polar covalent
1.7 ionic bond

Question 21

What does pH stand for

Answer 21

power of hydronium or hydrogen (chance of hydronium in a molecule)

Question 22

acidity and ph connection

Answer 22

H+; a higher chance for the power of hydrogen

Question 23

base and ph connection

Answer 23

a lower chanced for hydronium and hydrogen (OH-)