Biology Quiz 2 and 3 Study Guide

A substance which yields an anion plus a proton is a(n): salt acid base

acid

From your knowledge about the distribution of electrons in the levels and from the atomic number (in parentheses), indicate the most likely charge on the ion when this atom forms an ion. (Remember the 2, 8, 18 level distribution.) Hydrogen (1) 0 -1 +1 -2 +2

+1

From your knowledge about the distribution of electrons in the levels and from the atomic number (in parentheses), indicate the most likely charge on the ion when this atom forms an ion. (Remember the 2, 8, 18 level distribution.) Magnesium (12) 0 -1 +1 -2 +2

+2

An atom with six electrons in its n = 2 shell will become an ion with a charge of: + 6 - 6 + 2 - 2

-2

From your knowledge about the distribution of electrons in the levels and from the atomic number (in parentheses), indicate the most likely charge on the ion when this atom forms an ion. (Remember the 2, 8, 18 level distribution.) Oxygen (8) 0 -1 +1 -2 +2

-2

A plant must supply energy through photosynthesis in order for its complex starch molecules to turn to simple sugar. T/F

False

A substance that releases hydrogen ions in water is a base.

False

Of the known elements only about ten are needed by living things. T/F

False

Sodium and chlorine atoms combine readily because they both tend to lose electrons.

False

The number of protons within an atom of an element is equal to its atomic mass. T/F

False

Water can dissolve only inorganic compounds. T/F

False

A solution that contains equal numbers of hydrogen and hydroxide ions would be called: acidic basic alkaline neutral

Neutral

The heat needed for chemical reaction to take place is called _____. heat of reaction activation energy friction

activation energy

Substances which maintain a body's pH within narrow limits are called ________________________ .

buffers

All organic molecules contain the element _____. hydrogen oxygen nitrogen carbon

carbon

A substance that helps a reaction to take place, but does not participate in the reaction is called a(n) _____. catalyst reactant product activation energy

catalyst

Atoms that form compounds are held together by chemical bonds. The bond that includes sharing electrons with another atom is called______________

covalent

When electrons are shared, the type of bonding is called: ionic nuclear hydrogen covalent

covalent

Identify the type of chemical reaction. H 2 CO 3 H 2 O + CO 2 decomposition exchange reversible synthesis

decomposition

The n = 2 shell of an atom contains a maximum of: two electrons seven electrons eight electrons eleven electrons

eight electrons

When atoms combine, interactions occur between their: nuclei electrons protons neutrons

electrons

What is expected when reactants break bonds? energy output energy input equilibrium exchange reaction

energy output

A catalyst for chemical reactions in biological systems is called a(n) ____________________________ .

enzyme

A(n) ____________________________ reaction occurs when the bonds of the reacting compounds are broken and new combinations are formed.

exchange

Identify the type of chemical reaction. H 2 SO 4 + 2KOH K 2 SO 4 + 2H 2 O decomposition exchange reversible synthesis

exchange

The bonds that link many water molecules together to form a water drop are: ionic nuclear hydrogen covalent

hydrogen

If an atom loses or gains an electron, it is called a(n)______________

ion

Atoms which transfer electrons can combine to form a(n) ___________________________ bond.

ionic

(Select all that apply.) Choose the three types of bonds introduced. ionic molecular compound covalent hydrogen oxygen

ionic, covalent, hydrogen

If an atom has twelve electrons, how many electrons are in the n=1 energy level? How many electrons are in the n=2 energy level? How many electrons are in the n=3 energy level?

n=1 shell 2 n=2 shell 8 n=3 shell 2

When an atom gains an electron, it becomes _______________________ charged.

negatively

When an atom loses an electron, it becomes ___________________________ charged

positively

A(n) ________________________ reaction occurs when a molecule is formed from the bonding of atoms, ions or simpler molecules.

synthesis

Identify the type of chemical reaction. NH 3 + H 2 O NH 4 OH decomposition exchange reversible synthesis

synthesis

Chemical reactions are the result of an atom attempting _____. to reduce the number of electrons to become electrically neutral to rearrange its configuration to result in a stable octet add sufficient electrons to complete its outer shell

to rearrange its configuration to result in a stable octet

The n = 1 shell of an atom contains a maximum of: two electrons seven electrons eight electrons eleven electrons

two electrons

If the outer energy level of the atom is full, it ((DOES//DOES NOT)) react readily with other atoms.

Does not

The reactivity of an atom is due to the number and arrangement of ________________________in the outer energy level.

Electrons

A salt is produced when an acid reacts with a base.

True

An atom that has gained or lost electrons is called an ion.

True

The symbol Na + represents a sodium atom that has lost an electron.

True

________________ are compounds that produce H+ ions in solution.

acids