Which of these relationships is true of an uncharged atom?
The number of protons is equal to the number of electrons.
What determines the types of chemical reactions that an atom participates in?
the number of electrons in the outermost electron shell
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms are isotopes.
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
Atoms with the same number of protons but with different electrical charges _____.
are different ions
A covalent chemical bond is one in which
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms.
A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n) _____. (Concept 2.1)
Which of the following is a trace element required by most living organisms? (Concept 2.1)
Changing the number of _____ would change an atom into an atom of a different element. (Concept 2.2)
protons in an atom
How an atom chemically behaves when it comes into contact with other atoms is determined by its _____. (Concept 2.2)
Which of the following holds atoms together in a biological molecule? (Concept 2.3)
Nonpolar covalent bonding.
Polar covalent bonding
Van der Waals interactions
All of the above.
All of the above
Hydrogen bonding is most often seen _____. (Concept 2.3)
when hydrogen is covalently bonded to an electronegative atom
Chemical equilibrium is reached when _______ (Concept 2.4)
The forward and reverse reactions occur at the same rate so that the concentrations of reactants and products remain the same.
The tendency of an atom to pull electrons toward itself is referred to as its _____.
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds
In a neutral solution the concentration of _____.
hydrogen ions is equal to the concentration of hydroxide ions
Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemical bonds known as _____. (Concept 3.1)
Many of water's emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _____. (Concept 3.2)
are electrically attracted to each other.
The amount of energy that must be absorbed or lost to raise or lower the temperature of 1 g of liquid water by °C _____. (Concept 3.2)
is 1 calorie
Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water's _________. (Concept 3.2)
High Specific Heat
Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be _____. (Concept 3.2)
an aqueous solution
If the molecular mass of a carbon atom is 12, the mass of a hydrogen atom is 1, and the mass of an oxygen atom is 16 daltons, how many molecules does one mole of sugar (C12H22O11) contain? (Concept 3.2)
6.02 x 1023
An acid is a substance that _____. (Concept 3.3)
increases the hydrogen ion concentration of an aqueous solution
Select the statement that best describes a buffer. (Concept 3.3)
A buffer accepts hydrogen ions when they are in excess and donates hydrogen ions when they have been depleted.