Topic 2: Chemical Bonds + Water

Question 1

What are chemical bonds?

Answer 1

• bonds that hold atoms together to form molecules

Question 2

What are the two types of bonds?

Answer 2

• Ionic and covalent

Question 3

What are ionic bonds? Also, use NaCl as an example for what happens (3)

Answer 3

• ions formed
  ex. NaCl, where Na+ loses an electron and Cl- gains an electron
• the positive Na+ and negative Cl- ions ATTRACT, forming the bond
• in H2O, NaCl dissociates/separates into ions Na+ and Cl-

Question 4

What are covalent bonds?

Answer 4

• sharing electrons between atoms
• ex. O2, or CH4

Question 5

Chemical bonds allow for the formation of chemical compounds. These compounds may be _____ or _____.

Answer 5

Organic, inorganic

Question 6

What characterizes organic substances? Give 4 examples

Answer 6

• covalently bonded carbon atoms
• carbs, proteins, lipids, and nucleic acids

Question 7

What characterizes inorganic substances? (2)

Answer 7

• usually lacks carbon
• Note that ionically bonded carbons are inorganic
• eg. H2O, NaCl, O2

Question 7

What characterizes inorganic substances? (2)

Answer 7

• usually lacks carbon
• Note that ionically bonded carbons are inorganic
• eg. H2O, NaCl, O2

Question 8

There are some examples of inorganic compounds containing carbon atoms. Name them.

Answer 8

• Carbonic acid (H2CO3)
• Bicarbonate (HCO3-)
• Carbon Dioxide (CO2)
• Carbon Monoxide (CO)

Question 9

What is the most abundant substance in cells? About what percentage does it take up in cells?

Answer 9

• water
• about 55-60% water in a healthy, lean adult

Question 10

Water is a polar molecule. What does that mean?

Answer 10

• unequal sharing of electrons leads to a slight charge difference

Question 11

What are some reasons (in the notes) that water is important in the body? (3)

Answer 11

• Many reactions in the body take place in or involve H2O
• Transports chemicals (eg. O2, nutrients)
• Maintains body temperature at 37 degrees celsius