Biology Chapter 2 Review
Why does sweat cool off the human body?
Water has a high heat of vaporization.
Many of the first responders at the Chernobyl accident died within hours or days of working at the explosion site. What were they most likely to die from, and why?
acute radiation sickness due to exposure to ionizing radiation
An ionic bond involves _____.
an attraction between ions of opposite charge
Atoms with the same number of protons but with different electrical charges _____.
are different ions
The tendency of water molecules to stay together is called __________
cohesion
What type of bond is joining the two hydrogen atoms?
covalent
A(n) ____________ is a chemical bond in which atoms share a pair of electrons
covalent bond
A(n) _____ bond joins these two oxygen atoms.
double covalent
Which of the following lists of terms is in the correct order of size, going from smallest to largest?
electron, proton, nucleus, atom, molecule
The tendency of an atom to pull electrons toward itself is referred to as its _____.
electronegativity
Which part of the atom participates in a chemical bond?
electrons in the outer shell
Each water molecule is joined to _____ other water molecules by ____ bonds.
four ... hydrogen
The brackets are indicating a(n) _____ bond.
hydrogen
What name is given to the bond between water molecules?
hydrogen
Which of these bonds is weakest?
hydrogen bonds
What is the arrow pointing to?
hydrogen ion
In a neutral solution the concentration of _____.
hydrogen ions is equal to the concentration of hydroxide ions
____________ compounds will interact with water.
hydrophilic
What is the arrow pointing to?
hydroxide ion
In salt, what is the nature of the bond between sodium and chlorine?
ionic
A(n)__________ contains the same number of protons, but a different number of neutrons, than another form of the same element.
isotope
What force holds a molecule of NaCl together in an ionic bond?
magnetism
A(n) _____ refers to two or more atoms held together by covalent bonds.
molecule
Which of these atoms will be inert?
neon (10 electrons)
A(n) ___________ is a subatomic particle found in an atom's nucleus that has no electrical charge.
neutron
The unequal sharing of electrons within a water molecule makes the water molecule _____.
polar
In this molecule, what type of bond is found between the oxygen and hydrogens?
polar covalent
In addition to the risk of accidents, which of the following is a problem when nuclear power is used as a method of generating electrical power?
storage and disposal of spent fuel rods
Why isn't this insect drowning?
surface tension
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
10
The innermost electron shell of an atom can hold up to _____ electrons.
2
This atom can form up to _____ single covalent bond(s).
4
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
5
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
6
What is specific heat?
the energy necessary to change the temperature of a substance by 1oC
What determines the types of chemical reactions that an atom participates in?
the number of electrons in the outermost electron shell
What property of an atom determines which element it is?
the number of protons
Which basic property of a single water molecule accounts for all of its special features, including adhesion and cohesion, its ability to act as a solvent, and its high specific heat?
the polarity of water
Which of these effects results from the hydrogen bonding between water molecules and nothing else?
water having surface tension
How many covalent bonds can an atom usually make?
An atom can make a number of covalent bonds equal to the number of electrons it needs to fill its outer shell.
We may never know how many people became ill or died as a result of the Chernobyl accident. What is the main reason why this is so difficult to determine?
Cancer might not occur for many years after exposure to ionizing radiation.
Cancer is caused by DNA mutations. What exactly do cigarette smoke and radiation do that can cause cancer?
Cigarette smoke and radiation both cause free radicals, which damage DNA, leading to mutations.
The concrete sarcophagus enclosing the damaged reactor is crumbling, allowing radiation to leak out into the environment. An animation of a new protective cover is shown in the video. Why hasn't the construction of this cover been completed?
It will be extremely expensive to build.
How do atoms respond when they absorb energy?
Electrons move to a higher orbital
How do atoms respond when they absorb energy?
Electrons move to a higher orbital.
_________ compounds do not interact with water.
Hydrophobic
Why is ionizing radiation damaging to cells?
It knocks the electrons from the cell's molecules, forming ions and breaking bonds.
Coffee has a pH of 5.0. Stomach acid has a pH of 2.0. How does coffee compare to stomach acid?
Stomach acid is 1,000 times more acidic than coffee.
Sugar is a covalently linked compound with many atoms. Water is able to dissolve sugar. What does this suggest about the atoms of sugar?
Sugar must contain oxygen or nitrogen atoms.
How do the hydrogen bonds between water molecules compare to the covalent bonds within water molecules?
The hydrogen bonds are more easily broken than the covalent bonds.
Why does ice float?
The hydrogen bonds in solid water force the molecules farther apart than the same bonds in liquid water.
Although the forest is growing quickly around Chernobyl, and some of the wildlife is thriving, studies show that biodiversity around Chernobyl has been reduced by over 50% since the accident. Why?
The ionizing radiation affects the DNA of the wildlife, just as it affects the DNA of humans.
Which of these relationships is true of an uncharged atom?
The number of protons is equal to the number of electrons.
How does water dissolve salt?
The partial positive charges of the hydrogen atoms on water surround the negative charge of a chlorine ion.
Why is the town of Pripyat uninhabited?
The radiation levels in the town are still unsafe.
How does the pH of the solution on the right compare with that of the solution on the left?
The solution on the right is basic relative to the solution on the left.
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms are isotopes.