Which type of bond holds atoms together in a water molecule?
covalent
100
Which type of macromolecule is fat?
lipid
100
Which property of water is most significant in water's role as a universal solvent?
Water molecules have positive and negative sides.
100
According to the concept of entropy, over time, most molecules will ___________ ____________.
break down
200
How is an organic compound different from an inorganic compound?
Organic compounds contain carbon atoms bonded to other atoms.
200
What are hydrogen bonds?
Weaker bonds that form from molecules that have a slight positive charge on one side and a slight negative charge on the other.
200
A scientist tested a substance with the chemical indicator Sudan III. If the test is negative, which type of macromolecule is not present in the substance?
lipid
200
Cohesion and adhesion of water molecules are a direct result of what?
hydrogen bonding
200
What are ions?
charged particles
300
Why can a carbon atom bond with itself easily?
It has 4 valence electrons.
300
What is a valence electron?
an electron in the outer shell of an atom
300
If a scientist tests a substance using iodine, which macromolecule is the scientist testing for?
carbohydrate
300
Why does the oxygen atom in a water molecule have a slightly negative charge?
because it has a stronger pull on the electrons, causing them to reside closer to it
300
Atoms of which 3 elements could bond together to form an organic compound?
carbon, hydrogen, oxygen
400
Why is carbon present in so many types of molecules?
It can form up to 4 covalent bonds.
400
How many electrons does it take to fill the second electron shell of an atom?
8
400
If a scientist tests a substance with sodium hydroxide and copper sulfate solution, what is the scientist looking for?
protein
400
What makes water a polar molecule?
The slight negative charge on the oxygen side and the slight positive charge on the hydrogen side of the molecule.
400
Give two examples of trace elements found in organic compounds.
iron, calcium, magnesium, zinc, cobalt
500
Decribe the outer shell of a carbon atom.
It has 4 electrons.
500
What is an ionic bond?
A bond that results from the attraction between two charged atoms or molecules (ions).
500
Give an example of how a compound found in a different kind of organism can be used to benefit people.
Answers will vary.
500
What does it mean when we say that water is a universal solvent?
It can dissolve more substances than any other solvent.
500
What is a trace element?
an element found in very small amounts in living things