Chapter 2 Bio

What two subatomic particles have a relatively similar mass?

• protons and electrons

• croutons and protons

• electrons and neutrons

• protons and neutrons

What does the mass number refer to?

• the weighted average of all of the isotopes of an element

• the average number of protons and neutrons

• the number of protons and neutrons

• the atomic number

Isotopes are different "versions" of the same element. What makes isotopes different from one another?

•  

  they have different atomic numbers

   

• they have different mass numbers

• the have different amounts of protons

• their coloration

C¹⁴ and C¹² have similar __________. This is why they both can form CO2 and make their way into plant tissue.

• names

• origins

• properties

• number of neutrons

Electrons are _________ in ionic bonds.

• neutral

• shared

• transferred

• none of the above

A....is an atom that has either more or less electrons than protons.

• Ion

• Molecule

• Element

• Compound

In....electrons are shared.

• covalent bonds

• NaCl

• ionic bonds

• ionic compounds

An example of a molecular compound is ....

• 02

• N2

• CO2

• NaCl

Answer explanation

Molecular compounds are inorganic compounds that take the form of discrete molecules. Examples include such familiar substances as water (H2O) and carbon dioxide (CO2). These compounds are very different from ionic compounds like sodium chloride (NaCl).

How many valence electrons does nitrogen have?

• 5

• 14

• 3

• 7

How many valence electrons does chlorine have?

• 17

• 4

• 7

• 13