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Chapter 2 - CHS biology

Terms in this set (42)

Knowing the atomic mass of an element allows inferences about which of the following?
The number of protons plus neutrons in the element
In what way are elements in the same column of the periodic table the same? They have the same number of______.
Electrons in their valence shells when neutral
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers from 92-100. therefore , which of the following can be true?
Molybdenum atoms can have between 50 and 58 neutrons.
Van der Waals interactions may result when _____.
Electrons are not symmetrically distributed in a molecule.
Which of the following statements are false?
All life requires the same essential elements.
Carbon-12 is the most common isotope of carbon and has a mass number of 12. However, the average atomic mass of carbon found on a periodic table is slightly more than 12 daltons. Why?
Some carbon atoms in nature have more neutrons
Magnesium has an atomic number of 12. What is the most stable charge for a magnesium ion?
A +2 charge
From its atomic number of 15, it is possible to predict that the phosphorus atom has______.
15 protons and 15 neutrons
Which of the following best describes the relationship between the atoms described below?
They are isotopes
Fluorine has an atomic number of 9. Which of the following would you do to a neutral fluorine atom to complete its valence shell?
Add 1 electron
Which of the following is the best description of an atom's physical structure?
Atoms are little bubbles of space with mass concentrated at the center of the bubble
What one of the atoms shown would be most likely to form an anion with a charge of -1?
A
A covalent bond is likely to be polar when
One of the atoms sharing electrons is more electronegative than the other atom
If you change the number of neutrons in an atom you create_____.
An isotope
How many neutrons are present in the nucleus of phosphorus -3 (32P) atoms?
17
How many electrons will a single atom of sulfur with no charge and o bonds have in its valence shell?
6
Based on electron configuration, which of the elements in the rogue above would exhibit a chemical behavior most like that of oxygen?
Sulfur
Can the atomic mass of an element vary?
Yes. adding or losing neutrons will change the atomic mass without forming a different element
Bonds between two atoms that are equally electronegative are_____.
Nonpolar covalent bonds
A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a ______.
Surface of hydrocarbons
A covalent chemical bond is one in which _____.
Outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals
Nitrogen is more electronegative than hydrogen. Which of the following is a correct statement about atoms in ammonia?
Each hydrogen atom has a partial positive charge; nitrogen atom has a partial negative charge.
Which bond or interaction would be difficult to disrupt when compounds are put into water?
Covalent bonds between carbon atoms
Water molecules are attracted to one another by_____.
Hydrogen bonds
What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms?
6
If an atom has a charge of +1, which of the following must be true?
If it has one more proton than it does electrons
Elements found on the left side of the periodic table contain outer shells that are ____; these elements tend to form _____ in solutions.
Almost empty; cations
When are atoms most stable?
When all of the electron orbitals in the valence shell is filled.
Which of the following correctly describe all chemical equilibrium?
Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products.
Radioisotopes have unstable
Nuclei
Which of the following statements about hydrogen bonding is false?
Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms.
The chemical behavior of an atom if determined by
The outermost electron shell
the shape of a molecule is determined by the positions of the atoms' orbitals. This is important because shape determine how biological molecules
Recognize and respond to one another with specificity
Which of the following correctly describes a reaction that has reached chemical equilibrium?
The rate of the forward reaction is equal to the rate of the reverse reaction
Identify the reactant(s) in the chemical reaction. cO2+ h20 ---> h2co3
Co2 and h2o
If the half-life of carbon-14 is you 5730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?
22,900
Certain radioactive isotopes are useful in medicine to diagnose or treat disease because
Their half life is short enough to clear all of the radioactivity in a short period of time;
Cells cannot determine the difference between the radioactive and nonradioactive;
Detection devices are available to trace the radioactivity in the body.
Neutrons and _____ are found in the nucleus of an atom.
Protons
Of the three subatomic particles, ____ are the most involved in forming chemical bonds.
Electrons
Name of the most abundant molecule in any organism.
Water
The four most abundant element by weight in an organism will form what type of bind with each other to form molecules?
covalent
How many electrons are involved in a single covalent bond?
2 electrons