Chapter 2 Review Ap Bio

1.

There are _____ naturally occurring elements. The Correct Answer: 92

2.

Which of the following is a trace element? The Correct Answer: copper

3.

Which one of the following is not one of the four most abundant elements found in living systems? The Correct Answer: zinc

4.

Which one of the following has negligible mass? The Correct Answer: electron

5.

Which one of the following subatomic particles has appreciable mass and lacks a charge? The Correct Answer: neutron

6.

The number of protons in an uncharged atom _____. The Correct Answer: equals the number of electrons

7.

Consider a hypothetical atom with an atomic number of 4 and a net electronic charge of +1. How many neutrons does this atom have? (The Correct Answer: The answer cannot be determined from the information provided.

8.

An element has 8 protons, 9 neutrons, and 8 electrons. Its atomic number and atomic mass, respectively, are _____. The Correct Answer: 8 and 17

9.

Two atoms of the same element must have the same number of _____. (Concept 2.2 ) The Correct Answer: protons

10.

An uncharged atom of nitrogen (atomic number = 7) has _____. The Correct Answer: 7 protons and 7 electrons

11.

Isotopes of an element will always differ in _____. The Correct Answer: atomic mass

12.

A particular carbon isotope has an atomic number of 6 and an atomic mass of 14. The respective number of neutrons, protons, and electrons that this carbon isotope has is _____. The Correct Answer: 8, 6, and 6

13.

Phosphorus-32 (radioactive) has _____ than phosphorus-35 (normal). The Correct Answer: 3 fewer neutrons

14.

The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium? The Correct Answer: an atom with 20 protons, 21 neutrons, and 20 electrons

15.

Which of the following is not a characteristic that makes radioactive tracers useful in medical diagnoses? The Correct Answer: They may damage or destroy molecules.

16.

Potassium (atomic number 19, mass number 40) and sodium (atomic number 11, mass number 23) have similar chemical properties and reactive behavior. This is because uncharged atoms of potassium and sodium _____. The Correct Answer: have different mass numbers and each has 1 electron in its outermost electron shell

17.

Atomic chlorine has an atomic number of 17. It has _____ electrons in its third shell. The Correct Answer: 7

18.

The chemical characteristics or reactivity of an element depend mostly on the _____. The Correct Answer: number of electrons in its outermost shell

19.

Some groups of elements react chemically in similar ways. For example, the chemistry of sodium and the chemistry of lithium are similar. The chemistry of chlorine and the chemistry of iodine are also similar. These

similarities in chemistry result when different elements have similar _____. The Correct Answer: numbers of outer-shell electrons 20.

How many electrons would be present in the valence shell of a sulfur atom (atomic number 16, mass number 32)? The Correct Answer: 6 electrons

21.

For most atoms, a stable configuration of electrons is attained when the atom _____. The Correct Answer: has 8 electrons in its outermost shell

22.

An atom that normally has _____ in its outer shell would not tend to form chemical bonds with other atoms. The Correct Answer: 8 electrons

23.

A polar covalent bond is a bond that _____. The Correct Answer: has shared electrons pulled closer to the more electronegative atom

24.

A covalent bond is likely to be polar if _____. The Correct Answer: one of the atoms sharing electrons is much more electronegative

25.

When the proton number and electron number are unequal, the atom or molecule _____. The Correct Answer: is an ion

26.

A sodium atom has a mass number of 23. Its atomic number is 11. How many electrons does it have if it is not an ion? The Correct Answer: 11

27.

Copper has an atomic number of 29 and a mass number of 64. What would result if an uncharged copper atom lost two electrons? The Correct Answer: The atomic number would remain 29, the mass number would remain 64, and the atom would be a cation with a +2 charge.

28.

The compound CaSO4 ionizes into a calcium ion and a sulfate ion (SO4). Calcium has 2 electrons in its outer shell. Upon ionization, what would you

expect the charge on the sulfate ion to be? 29.

Ionic bonds form as a result of _____. The Correct Answer: attraction between atoms that have opposite charges

30.

A hydrogen bond _____. The Correct Answer: is a weak chemical bond

31.

Which is not involved in, or is not relevant to, hydrogen bondingThe Correct Answer: loss of electrons

32.

Hydrogen bonds occur when _____. The Correct Answer: partial opposite charges on molecules come close enough to attract each other

33.

Which of the following molecules has the shape of a completed tetrahedron? The Correct Answer: methane (CH4)

34.

Which of the following statements is not true about chemical reactions? The Correct Answer: They represent the way matter is created and destroyed.

35.

Which one of the following does the equation of a chemical reaction not tell us? The Correct Answer: the speed of the reaction

36.

Which of the following statements describes a reversible reaction that has reached chemical equilibrium? The Correct Answer: The rate of the reverse reaction equals the rate of the forward reaction.