AP Biology Chapter 2

Multiple Choice

Which of the following food items is like a compound?

• a glass of pure water

• a sandwich containing ham, lettuce and tomato

• an ice cube

• a plain baked potato

• an ear of corn

Multiple Choice

Which of the following is a trace element in the human body?

• Carbon

• Oxygen

• Nitrogen

• Phosphorus

• Hydrogen

Multiple Choice

What do elements with atomic numbers 6, 14, and 22 have in common?

• Same number of electrons

• Same atomic mass

• Same number of valence electrons and will form the same number of covalent bonds

• All of the above

• None of the above

Multiple Choice

Titanium has an atomic number of 22. How many protons, neutrons, and electrons are in an isotope of titanium with mass number of 48?

• p = 22, n = 26,

  e = 22

• p = 11, n = 26, e = 11

• p = 11, n = 26, e = 70

• p = 11, n = 22, e = 48

• p = 22, n = 22, e = 48

Multiple Choice

Carbon-14 dating works for fossils up to about 75,000 years old. Most dinosaurs went extinct 65.5 million years ago. Can ¹⁴C be used to date dinosaur bones?

• Yes; the bones continued to take in ¹⁴C, even after the dinosaur died.

• No; the ¹⁴C present in the dinosaur when it died would decay too much to be measured after 65.5 million years.

• No; ¹⁴C can only be used to date dinosaur teeth, which are much stronger than bones.

• Yes; the bones contained ¹⁴C when the dinosaur died, so ¹⁴C can be used to determine the fossil's age.

Multiple Choice

Radioactive uranium-235 has a half-life of 704 million years. If it was incorporated into dinosaur bones, could it be used to date the dinosaur fossils?

• Yes; after 65.5 million years, only about one-tenth of the ²³⁵U would have decayed, leaving plenty to measure in the fossils.

• No; the dinosaurs went extinct too recently to use a radioisotope with a half-life of 704 million years.

• No; only about one-tenth of the ²³⁵U would have decayed after 65.5 million years, not leaving enough to measure in the fossils.

• Yes, but only for dinosaurs that lived more than 704 million years ago.

Multiple Choice

Which of the following indirectly determines the bonds that an atom can form?

• protons

• neutrons

• electrons

Multiple Choice

An atom of oxygen has an atomic number of 8. How many electrons are in the first, second, and third electron shells, respectively?

• 2, 3, 3

• 2, 6, 0

• 8, 0, 0

• 0, 4, 4

• None of the above

Multiple Choice

Based on the periodic table shown here, which elements will most likely form a covalent bond?

• Na and Cl

• C and O

• N and O

• Si and Cl

• H and H

Multiple Choice

Based on the periodic table shown here, which elements will most likely form an ionic bond?

• Na and Cl, Li and F

• C and O

• N and O

• Si and Cl

• All of the above

Multiple Choice

A person carefully walking on a slippery sidewalk is most like which kind of bond?

• ionic

• polar covalent

• hydrogen

Multiple Choice

What type of bond is very prevalent in lipids and gives lipids their hydrophobic properties?

• Polar Covalent

• Non-polar Covalent

• Strong Ionic

• Weak Ionic

• Hydrogen

Multiple Choice

What would an electron holding extra energy be useful for?

• powering a biochemical process that requires energy

• storing energy for a time

• stabilizing a lipid molecule

• a and b

• a and c

Multiple Choice

You find a bacterium growing in pure oil, containing the usual hydrophobic lipids. This organism must be very good at breaking down_____.

• polar covalent bonds

• hydrogen bonds

• ionic bonds

• nonpolar covalent bonds

• all of the above

Multiple Choice

Which of the following is a product of photosynthesis that is a reactant in a campfire?

• glucose

• sunlight

• oxygen

• water

• all of the above

Multiple Choice

Think of squirrels entering and leaving a room as an analogy for a chemical reaction. When is the room at equilibrium?

• when equal numbers of squirrels are entering and leaving the room

• when all of the squirrels in the room leave

• when as many squirrels enter as there is space in the room

• when the door is shut

Multiple Choice

What numbers must be placed as coefficients in the blanks for the chemical reaction below in order to ensure that matter is conserved?

Fe₃O₄ + C⟶ _Fe + _CO

• 1; 1; 1

• 4; 3; 4

• 2; 1; 2

• 3; 4; 3

• 0; 3; 4