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