The smallest unit of matter that can enter into chemical reactions and is nondivisible by chemical means is called a(an) ______.
What does the nucleus of an atom contain?
|D)||protons and electrons|
|E)||protons and neutrons|
The atomic weight of an atom is equal to the number of ______ plus the number of ______.
Atomic weights have a single exact value for each element.
Which of the following statements is true?
|A)||Electrons have a negative charge and equal the number of neutrons.|
|B)||Electrons have a negative charge and equal the number of protons.|
|C)||Protons have a positive charge and equal the number of neutrons.|
|D)||Protons have a positive charge and are the main unit that helps bond atoms to each other.|
Electrons that have the greatest amount of energy are located in shells farthest from the nucleus.
What determines the chemical properties of an atom?
|A)||the number of electrons in the first shell|
|B)||the number of electrons in the outer shell|
|C)||the number of protons in the first shell|
|D)||the number of protons in the outer shell|
|E)||the number of neutrons in the outer shell|
In an electrically neutral atom, the number of ______ is equal to the number of ______.
The carbon atom has an atomic number of 6 and an atomic weight of 12. Therefore, a carbon atom has ______ protons.
______ are atoms that have the same number of protons but differ in the number of neutrons.
Chlorine has an atomic number of 17 and an atomic weight of 35. When chlorine becomes the chloride ion, its charge is ______.
Chlorine has an atomic number of 17. How many electrons are in the outermost shell?
The sodium atom has an atomic number of 11 and an atomic number of 23. Therefore, there are two electrons in the outermost orbit.
The molecule, K+Cl-, is held together by ______ bonds.
Atoms such as sodium, potassium, calcium or hydrogen, all gain electrons and become negatively charged.
If an atom either gains or loses an electron, the atom is called a(an) ______.
Double and triple bonds are ionic bonds where two or three electrons are lost or gained.
Atoms react with one another in order to achieve four electrons in their outer shell.
Which type of bond will share electrons between atoms?
When two nonmetal oxygen atoms (atomic number = 8) react with each other, they ______.
|A)||each give up two electrons|
|B)||each take two electrons|
|C)||each need six electrons|
|D)||each need eight electrons|
Complete this chemical reaction: HCl + NaOH ---------->
|A)||NaOH + HCl|
|B)||HCl + NaCl|
|C)||NaOH + NaCl|
|D)||NaCl + HOH|
|E)||NaCl + HCl|
In this reaction, K + Cl -----> K+Cl-, which element has been reduced?
|C)||both potassium and chlorine|
Oxidation refers to the ______.
|A)||loss of electrons and/or hydrogen atoms|
|B)||loss of electrons and the gain of hydrogen atoms|
|C)||gain of electrons and/or hydrogen atoms|
|D)||gain of electrons and the loss of hydrogen atoms|
If there are three pairs of electrons that are shared between two atoms, a(an) ______ is formed.
Suppose that you have this chemical formula: 5 H2O. Which of the following statements is FALSE?
|A)||There are five molecules of water.|
|B)||Water is composed of three different kinds of atoms.|
|C)||There are two atoms of hydrogen for every one atom of oxygen in one water molecule.|
|D)||There is a total of five oxygen atoms present.|
|E)||There is a total of 10 hydrogen atoms present.|
An individual water molecule is held together by ______.
Many water molecules are weakly held together by ______.
Which of the following statements is NOT a true characteristic of water?
|A)||Hydrogen bonding causes water molecules to be cohesive.|
|B)||Without hydrogen bonding, water would be gaseous at room temperature.|
|C)||Water absorbs a great deal of heat before it evaporates.|
|D)||Water keeps an animal's body temperature within normal limits.|
|E)||Because of hydrogen bonding, liquid water is less dense than ice.|
Water, being a nonpolar molecule, acts as a solvent.
Bases, when added to water, increase the hydrogen ion concentration.
______ are molecules that dissociate in water, releasing hydrogen ions.
If the concentration of hydrogen ions was 1 x 10-6,, the pH is ______.
At which pH will the concentration of hydrogen ions be equal to the concentration of hydroxide ions?
As the pH scale decreases, there is a two-fold increase in hydrogen ion concentration for every pH unit.
When hydrochloric acid, a strong acid, is added to water, the pH of water ______.
|B)||stays the same|
|D)||goes first up and then down|
______ are chemicals or combinations of chemicals that take up excess hydrogen ions or hydroxide ions in order to keep the pH constant.
Acids have a pH that is greater than 7, whereas bases have a pH that is less than 7.
If the hydrogen ion concentration in water was 0.0000001, the pH is ______.
Which atoms are always found in organic molecules?
|A)||carbon and hydrogen|
|B)||carbon and oxygen|
|C)||carbon and nitrogen|
|D)||oxygen and nitrogen|
|E)||oxygen and hydrogen|
Which of the following is NOT an organic molecule?
Which of the following statements is NOT correct about organic molecules?
|A)||Organic molecules are often associated with living organisms.|
|B)||Organic molecules always have ionic bonding between atoms.|
|C)||Organic molecules always contain carbon and hydrogen.|
|D)||Organic molecules may be quite large, with many atoms.|
Carbohydrates are macromolecules composed of ______ monomers.
|C)||glycerol and fatty acid|
______ is the process of splitting of a bond within a larger molecule by the addition of water.
______ is the process in which water is removed when two monomers join to form a macromolecule.
When dipeptide, disaccharide, and a triglyceride molecules are formed, water molecules are released during the condensation synthesis reaction of each.
Glucose, fructose, and galactose are all monosaccharides with the same molecular formula C6H12O6.
Glucose is the immediate energy source of the body.
Pentoses are sugars that have six carbon atoms.
Glycogen is the storage form of glucose in plants.
Maltose is a disaccharide composed of glucose and fructose.
Which type of organic molecule has the ratio of hydrogen atoms to oxygen atoms of approximately 2:1?
Glucose, fructose, and galactose are all classified as ______.
Which type of organic macromolecule is used primarily for energy and structure?
Which of the following molecules is NOT a polysaccharide?
Which type of carbohydrate is found in plant cell walls and accounts in part for the strong nature of these walls?
At room temperature, fats are liquids and oils are solids.
Glycerol and fatty acid are the monomers for most ______.
______ occurs when an oil droplet is dispersed in water.
A saturated fatty acid contains more ______ atoms than the same unsaturated fatty acid.
When glycerol combines with three fatty acids, a (an) ______ molecule results.
______ are lipids containing phosphorus that are very important in cell membranes.
A soap is a salt formed from an amino acid and an inorganic base.
Which type of organic molecule is used for long-term energy storage, insulation against heat loss, and forms a protective cushion around major organs?
Which type of lipid has four fused carbon rings?
Fats do not mix with water because they are polar molecules.
Which of the following molecules is NOT a steroid?
Which type of organic macromolecule represents a source of cell steroids and yet is found within membranes?
The polar portion of the phospholipid molecule (head) is soluble in water, whereas the two hydrocarbon chains (tails) are not.
A (An) ______ has a hydrocarbon chain (a string of carbon atoms with hydrogen atoms attached) and ends with the acid group -COOH.
Proteins are polymers of ______.
|C)||glycerol and fatty acid|
Amino acids are the same except for their R group.
What is the name of this functional group: -COOH ?
The bond that occurs between the acid group of one amino acid and the amino group of another amino acid is termed a (an) ______ bond.
A ______ is a string of 100-1000 amino acids joined by peptide bonds.
Which of the following types of organic molecules have their monomers joined by a peptide bond?
Oxygen and hydrogen atoms associated with a peptide bond share electrons in such a way that the oxygen carries a partial positive charge and the hydrogen carries a partial negative charge.
Which type of organic molecule sometimes has a structural role and may act as an enzyme?
When a strong acid is added to milk, the milk curdles. This is an example of protein denaturation.
When proteins are exposed to extreme pH, they can undergo an irreversible change in shape.
What is the final three-dimensional shape of a protein called?
The _______ structure of a protein is the linear sequence of the amino acids joined by peptide bonds.
Hemoglobin is a complex protein having a quaternary structure.
The ______ structure of a protein comes about when the polypeptide chain takes a particular orientation in space.
What are the components of a nucleotide?
|A)||glucose, cholesterol, triglyceride|
|B)||amino acid, fatty acid, phosphate|
|C)||phosphate, glucose, fatty acid|
|D)||phosphate, hexose sugar, nitrogen-containing base|
|E)||phosphate, pentose sugar, nitrogen-containing base|
When nucleotide monomers join together, the ______ polymer is formed.
The backbone of a nucleic acid is composed of ______.
|A)||the nitrogen bases|
|E)||the R groups|
______ molecules are characterized by having two strands of nucleotide polymers held together by hydrogen bonds.
Which organic macromolecules are used for reproduction and to control protein synthesis?
Which molecule functions as an energy carrier in cells?
Which pair below is mismatched?