Chapter 2 and 5
Molybdenum atoms can have between 50 and 58 neutrons.
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers of 91,94,95,96,97,98, and 100. Therefore, which of the following can be true?
They are isotopes.
Which of the following best describes the relationship between the atoms described below?
Atom 1 Atom 2
The element may have multiple stable isotopes, and the isotopic composition may vary from sample to sample.
The precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the standard atomic mass, or even from sample to sample. Why?
an electron may move to an electron shell farther away from the nucleus.
Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that...
Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom?
a surface made with carbon and hydrogen atoms covalently bonded together.
If a salamander relied on hydrogen bonds to cling to surfaces, what type of surface would cause the most problems for this animal?
If an atom of sulfur ( atomic number 16) were allowed to react with atoms of hydrogen (atomic number 1), which of the molecules below would be formed?
a Nonpolar covalent bond.
When two atoms are equally electronegative, they will interact to form...
a polar covalent bond.
What results from an unequal sharing of electrons between atoms?
Forward and reverse reactions continue with no effect on the concentrations of the reactants and products.
Which of the following correctly describes chemical equilibrium?
Which drawing in the figure above depicts the electron configuration of an atom capable of forming three covalent bonds with other atoms?
Which drawing in the figure above depicts an atom with a valence of 2?
In the figure above, how many unpaired electrons does phosphorus have in its valence shell?
Will form hydrogen bonds with water molecules.
The illustration above shows a representation of formic acid. A formic acid molecule.
the configuration of the sp hybrid orbitals of the electrons shared between the carbon and hydrogen atoms.
What causes the shape of the molecule shown above?
Which one of the atoms shown would be most likely to form a cation with a charge of +1?
Which of the following pairs of atoms would be most likely to form a polar covalent bond?
one more neutron
Compared with 31p, the radioactive isotope 32P has
the existence of unpaired electrons in the valence shell.
The reactivity of an atom arises from...
both 180 grams of glucose and 6.02x10^23 molecules of glucose.
One mole of glucose is
Dissolve 180g of glucose in .8L of water, and then add more water until the total volume of the solution is 1L.
the molar mass of glucose is 180g/mol. Which of the following procedures should you carry out to make a 1M solution of glucose
12.04 x 10^22
You have a freshly prepared 1 M solution of glucose in water. you carefully pour out a 200 mL sample of that solution. How many glucose molecules are included in that 200 mL sample?
How many grams would be equal to 1 mol of the compound shown in the figure about? (Carbon = 12, oxygen = 16, hydrogen = 1)
what is the chemical reaction mechanism by which cells make polymers from monomers
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule mad by linking three glucose molecules together by dehydration reactions?
A molecule w/ the chemical formula C18H36O2 is probably a...
They are insoluble in water.
Which of the following statements is true for the class biological molecules known as lipids?
they are the principal molecules in lard and butter.
which of the following is true regarding saturated fatty acids?
Leucine would be in the interior and serine would be on the exterior of the globular protein.
The R group or side chain of the amino acid serine is -CH2-OH, the R group or side chain of the amino acid leucine is CH2-CH-(CH3)2.
In the interior of the folded protein, away from water, or in a transmembrane portion interacting with lipid fatty acid chains.
In a normal cellular protein, where would you expect to find a hydrophobic amino acid like valine?
If 14C-labeled uridine triphosphate is added to the growth medium of cells, what macromolecules will be labeled?
Guanine and adenine
Which of the following are nitrogenous bases of the purine type?
If a DNA sample were composed of 20% thymine, what would be the percentage of guanine?
contains one less oxygen atom.
the difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA
If one strand of a DNA molecule has the sequence of bases 5'ACGTTA3''the other complementary strand would have the sequence
both proteins and nucleic acids
If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled?
it is a saturated fatty acid and a diet rich in the molecule may contribute to atherosclerosis.
which of the following statements is true regarding the molecule illustrated in figure 5.2?
C60 H202 O101
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking 20 glucose molecules together by dehydration reactions?