Chapter 2

Question 1

About 25 of the 92 natural elements are known to be essential to life what four of these 25 elements make up approximately 96% of living matter?

Answer 1

Carbon, hydrogen, nitrogen, and oxygen

Question 2

Trace elements are those required by an organism and only minute quantities, which is a trace element that is required by humans and other vertebrates, but not by other organisms, such as bacteria or plants?

Answer 2

Iodine

Question 3

True or false some natural occurring elements are toxic to organisms

Answer 3

True

Question 4

Why doesn’t an atom have an electric charge?

Answer 4

Because they have an equal number of protons and electrons

Question 5

A neutral atom has 2, 8, 8 electrons in its first second and third energy level is this information does not provide what?

Answer 5

It does not tell us about the atomic mass of the element

Question 6

Elements 72ZN 75AS and 74GE have the same amount of what?

Answer 6

They have the same number of neutrons

Question 7

A salamander relies on hydrogen bonding to stick to various surfaces. therefore a salamander would have the greatest difficulty clinging to what type of surface

Answer 7

Surface of hydrocarbons

Question 8

Nitrogen is more electronegative than hydrogen. What is a correct statement about the atoms in ammonia?

Answer 8

Each hydrogen atom has a partial positive charge. The nitrogen atom has a partial negative charge.

Question 9

What type of bond between two atoms that are equally electronegative?

Answer 9

Nonpolar covalent bonds

Question 10

What bond or interaction will be difficult to disrupt when compounds are put into water?

Answer 10

Covalent bonds between carbon atoms 

Question 11

How does a Van see waals interaction occur?

Answer 11

Electrons are not symmetrically distributed in a molecule

Question 12

What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms?

Answer 12

Six

Question 13

What causes a tetrahedral shape in a molecule?

Answer 13

The shape of the SP three hybrid orbitals of the electrons shared between the carbon and hydrogen atoms

Question 14

Based on electron configuration, which of the elements in the figure with exhibit, a chemical behavior more like that of oxygen?

Answer 14

Sulfur

Question 15

An atom has four electrons in its valence shell. What type of covalent bonds is it capable of forming?

Answer 15

Single double or triple

Question 16

What did trace elements mean?

Answer 16

Element is required in very small amounts

Question 17

What is chemical equilibrium?

Answer 17

Forward and reverse reactions continue with known that affect on the concentrations of the reactants and products

Question 18

Where does the reactivity of an atom arise from?

Answer 18

It arrives from the existence of unpaired electrons in the valence shell