Biology- Chapter 2 SB Questions

No orbital can contain more than ______.

2 electrons

How do ions in a crystal matrix interact?

Each ion is attracted to all of the oppositely charged ions in its vicinity.

It takes work to keep electrons in their orbitals due to which of the following?

Electrons are attracted to the nucleus.

In order for an electron to move to a more distal orbital which of the following must occur?

Energy must be added.

Which of the following are molecular formulas?

H2 O2

Select the polar molecule

H2O

Select the reasons that the molecule formed by two hydrogen atoms (H2) is stable.

It has no unpaired electrons. It is held together by a covalent bond. It has no net charge.

Electrons are attracted to the positive charge of the nucleus, therefore, which of the following is true?

It takes work to keep them in their orbitals.

Electrons in the same energy level ______.

always have the same potential energy

Water consists of one oxygen atom joined to two hydrogen atoms by what type of bonds?

covalent

Subatomic particles called ________ can be found at various distances from the nucleus

electrons

If two atoms are joined by a polar covalent bond, the shared electrons will tend to stay closer to the atom with ______.

higher electronegativity

12C, 13C, 14C

isotopes

The ________ charges produced by a polar covalent bond are much smaller than the unit charge of an ion.

partial

A(n) ______ covalent bond is formed by when one or more electron pairs are unequally shared between two atoms.

polar

Chemical reactions that involve a transfer of electrons from one atom to another are called _______ reactions

redox

An electrically neutral atom has an atomic number of 11 and an atomic mass of 23. This atom has ______protons, ______ neutrons, and _______ electrons.

11, 12,11

An atom has 11 protons, 12 neutrons, and 10 electrons. This atom has an atomic number of ______, an atomic mass of______, and an overall charge of ______.

11, 23, +1 (the charge of an atom is the number of protons minus the number of electrons)

If an atom has 6 electrons in its outermost layer, how many covalent bonds must it form in order to have a stable outer shell of electrons?

2

In a single covalent bond, ______ total electrons are shared (please enter the number of shared electrons).

2

This question refers to elements in the main groups of the periodic table. According to the octet rule, if an atom's first energy level is the outermost shell then it is stable with_______ electrons and if an atom has any other energy level as its outermost shell then it is stable with ______ electrons.

2;8

If an atom has 4 electrons in its outermost energy level, how many covalent bonds must it form in order to have a stable outer shell of electrons?

4

In a double covalent bond, ______ total electrons are shared (please only enter the number of shared electrons).

4

An electrically neutral atom has an atomic number of 6 and an atomic mass of 14. This atom has _________ protons __________neutrons, and ________ electrons.

6,8,6

An atom has 8 protons, 9 neutrons, and 8 electrons. This atom has an atomic number of Blank______, an atomic mass of Blank______, and an overall charge of Blank______.

8; 17; 0

Choose the four most abundant elements in living organisms.

Carbon Nitrogen Hydrogen Oxygen

_________ atoms always have one proton

Hydrogen

Of the following list of bonds and interactions, which one is the weakest?

Hydrophobic interaction

What is true of a molecule of gaseous hydrogen (H2)?

It has no net charge.

What type of bond forms between 2 hydrogen atoms?

Nonpolar covalent

Which of the following molecules are nonpolar?

O2 CH4 N2

Which of the following are structural formulas?

O=O, H-H

Electrons with the same potential energy always occupy which of the following?

The same energy level

Atoms are chemically the most stable when which of the following occurs?

Their outer shell is full.

A neutral atom has no net electrical charge. Why?

There are equal numbers of protons and electrons in the atom.

Which of the following statements about polar molecules are true?

They are electrically neutral. The distribution of electrical charge is not uniform. They have the same number of protons and electrons.

Choose all statements that describe atoms that have unfilled electron shells?

They can form chemical compounds. They can form bonds with other atoms They are chemically reactive.

The different energy levels of electrons within atoms can be described as which of the following?

They can only take certain discrete values that correspond to quanta

If two atoms belong to the same element, which of the following must be true?

They must have the same number of protons.

Which of the following correctly describes electrons within atoms?

They occupy discrete energy levels.

The crystal of the ionic compound NaCl is composed of ______.

a matrix of ions with a precise geometry

When NaCl is formed, ______.

a sodium atom loses an electron, while a chlorine atom gains an electron

A chlorine atom that has gained an electron and has an overall negative charge is an example of a(n) ______.

anion

A chlorine atom that has gained an electron and has an overall negative charge is an example of a(n) _______

anion

Atoms with a net negative charge are known as______ , whereas atoms with a net positive charge are known as______

anions, cations

True, discrete molecules form when atoms are connected by ______.

covalent bonds

Carbon-12, carbon-13, and carbon-14 are ______.

different isotopes of the same element

The volume of space around the nucleus where an electron is most likely to be found is known as which of the following?

electron orbital

The affinity of an atom for an electron is also known as which of the following?

electronegativity

A nonpolar covalent bond involves an equal sharing of one or more pairs of_______

electrons

An atom is composed of a central nucleus which is surrounded by which orbiting particles?

electrons

Atoms differ in their affinity for _______, a property called electronegativity.

electrons

If an atom gains or loses a(n) ________ it acquires a net electrical charge and becomes an ion.

electrons

Redox reactions involve a transfer of ______ from one atom to another.

electrons

The chemical behavior of an atom is determined by the number and configuration of its ______.

electrons

The chemical behavior of an atom is determined by the number and configuration of its_____

electrons

A substance that cannot be broken down into simpler substances by ordinary chemical means is called a(n) __________

element

When electrons move closer to the nucleus,______.

energy is released

When referring to atomic structure, the letters K, L, M, and so on are used to designate ______.

energy levels

___________ atoms usually have no neutrons.

hydrogen

The atoms in NaCl are held together by what type of bond?

ionic

Unlike______ bonds, which produce a crystal lattice,________ bonds are formed between 2 individual atoms, giving rise to true, discrete molecules.

ionic, covalent

Atoms, in which the number of electrons does not equal the number of protons, are called

ions

Electrons that are closer to the nucleus always have which of the following?

less potential energy

When writing out structural formulas, covalent bonds are represented by solid _____ between atomic symbols.

lines or dashes

A group of atoms held together by chemical bonds in a stable association is called which of the following?

molecule

s made of two or more atoms held together by chemical bonds in a stable association. The atoms may or may not belong to the same element.

molecule

Electrons that are farther from the nucleus have

more potential energy

Isotopes are atoms of the same element that differ in the number of which of the following?

neutrons

Isotopes differ in the number of_______ they contain.

neutrons

The atomic mass of an atom is equal to the sum of the masses of its and

neutrons, protons

Elements possessing all eight electrons (two for helium) in their outer energy level are ______.

noble gases, inert

A(n) ______ covalent bond involves an equal sharing of one or more pairs of electrons.

nonpolar

What type of bond forms between 2 identical atoms?

nonpolar covalent

Almost all the mass of an atom is located in the

nucleus

Where is most (almost all) of the mass of an atom located?

nucleus

Generally speaking, an atom is made of a central ________ which is surrounded by orbiting_________.

nucleus, electrons

electron ______ represent probability distributions for electrons, that is, regions surrounding the nucleus where there is the highest probability of finding electrons.

orbital

The term________ is used to designate the process of an atom losing one or more electrons while undergoing a chemical reaction

oxidation

If two atoms are joined by a polar covalent bond, the atom with the lower electronegativity will have a partial ______ charge.

positive

A cation has a net _____ charge, while an anion has a net _____ charge.

positive, negative

Atoms of the same element always have the same number of protons ____________ in the nucleus, and this number is unique for that element.

protons

The atomic number of an element refers to the number of __________ in the atoms of that element.

protons

Which subatomic particles determine the atomic mass of an atom?

protons and neutrons

Which two particles are the primary determinants of an element's atomic mass?

protons and neutrons

Atoms of different chemical elements can be differentiated based on the number of ______.

protons in the nucleus

Which subatomic particles are located in the nucleus of an atom?

protons, neutrons

Which of the following are subatomic particles?

protons, neutrons, electrons

Within an atom, ______ and ______ have nearly equal masses, while ______ have a much smaller mass.

protons, neutrons, electrons

An atom participating in a chemical reaction gains one or more electrons. The process of gaining electrons in a reaction is called_______

reduction

Regardless of their shape and position, electron orbitals can never contain more than____ electrons.

two

Electrons in outer, unfilled energy levels are known as _________ electrons.

valence

The number and configuration of electrons determines an element's ______.

chemical properties

In structural formulas, each solid line between atomic symbols represents a single______ bond.

covalent

matter

any substance that has mass and occupies space

If two atoms have the same number of protons in their nucleus, you can conclude for sure that they ___________

are atoms of the same element

In a neutral atom, the number of electrons is equal to which of the following?

atomic number

ions

atoms in which the number of electrons does not equal the number of protons. they are charged particles

A sodium atom that has lost an electron and has an overall positive charge is an example of which of the following?

cation

Valence electrons and their interactions determine the _______ properties of an element.

chemical