Chemistry Re-cap

The uranium atom has a mass number of 238 and an atomic number of 92. How many neutrons?

146.

The element phosphorous (P) has an atomic number of 15 and a mass number of 31. How many neutrons does P carry?

16.

The atomic mass of hydrogen is 1 and that of oxygen is 16. The molecular mass of water, H2O, which consists if 2H and 1O, is (2 x 1) + (1 x 16), or 18. Therefore, one mole of water has a mass of

18 grams.

The maximum number of electrons in the 3rd energy level is

18. (n = 3)

What is the molecular mass of glucose, C6H12O6?

180 grams. Atomis masses are: C = 12 H = 1 O = 16

Helical structure of DNA

1953 Crick and Watson

For the helium atom to have a mass number of 4, the 2 neutrons must contain how many daltons?

2

When sand is placed in water and shaken,

a sand-water suspension is produced.

The hydrogen concentration of water is 10 -7. What is the pH of water?

7.

The pH of blood (a buffer solution) lies in the range of

7.35-7.45.

For the second energy level, n=2, the max number of electrons is

8.

Uranium is the most complicated of the elements that occur naturally. A uranium atom contains 92 protons, 146 neutrons, and 92 electrons. The atomic number of uranium is

92.

While diffusion is taking place, osmosis can also occur;

During osmosis, water flows through a membrane from a hypotonic solution to a hypertonic solution.

The following solutions are all examples of electrolytes:

MgCl4 (Salt) Mg2 + SO42- KOH (Base) K+ + OH- HNO3 (Acid) H+ + NO3-

What ion does active transport pump out of the cell?

Na+

Is MgCl2 an acid, base, or a salt?

Salt (It contains no OH- or H+ ions therefore, cannot be an acid or base)

Electrons make up the electron cloud, which may be subdivided into different energy levels.

The first energy level is nearest to the nucleus; then comes the second energy level, the third energy level, and so on.

Each energy level can hold a certain number of electrons. This maximum number may be determined by using the formula:

X is the max number of electrons in energy level number n

A nonpolar compound is

a covalent bond in which electrons are shared equally.

If 2 neutrons have a total of 2 daltons,

a neutron must have an atomic mass of 1.

The outer part of the atom, which contains electrons, is called the

electron cloud.

An ion is an atom that has acquired an electrical charge by either losing or gaining a(n)

electron.

The first energy level must be filled with 2 electrons before

electrons can go to the second energy level.

Atoms are made up of several components. Collectively these components are called the

elementary particles.

n =

energy level number

Osmosis will continue until the concentrations of the solute and solvent on either side of the membrane are

equal.

A log, or logarithm, is an

exponent.

Osmolarity is the method of

expressing solution concentration based on the number of particles in solution.

A weak base (closer to 7) reacts with relatively

few H+ ions.

Radioisotopes, isotopes that give off radiation, are

frequently used in medical applications.

In a % solution, the % number indicates the number of

grams of solute present in 100 mL of a solution. The solvent is usually water.

Carbon atom with mass number of 13

has an added neutron.

A suspension is

heterogeneous mixture containing a liquid in which visible particles settle.

A solution is

homogeneous mixture.

Diffusion is the flow of solute particles from a

hypertonic (concentrated) solution to a hypotonic (diluted) solution.

A solution that has a HIGHER solute concentration than another solution is said to be

hypertonic when compared to the second solution.

A solution that has a LOWER solute concentration than another solution is said to be

hypotonic when compared to the second solution.

I-131 (radioactive iodine, also written as 131-I) is used

in the diagnosis and treatment in thyroid conditions.

Because the electrons, which have practically no mass, are located outside the nucleus, the entire mass of the atom can be considered to be located

in the nucleus.

After depolarization, sodium channels quit allowing ions

into the cell, and potassium begins to be pumped out of the cell.

Sodium flows

into the cell.

CH3OOH (Acetic Acid)

is a weak acid and yields few H+ ions.

Electronegativity

is the attraction of an atom for electrons.

A solution that has the SAME solute concentration as another solution is said to be

isotonic when compared with the second solution.

When atoms of a metal and a nonmetal react, the difference in electronegativities is relatively

larger and an ionic bond results.

Because both Na+ and K+ are positively charged ions, 3 positive charges are pumped out of a cell for every 2 that are pumped in. Should the inside of the cell be more positive or less positive than the outside of the cell?

less

One general rule of solubility is that

like dissolves like. That is, polar liquids dissolve polar compounds, and nonpolar liquids dissolve nonpolar compounds.

A buffer solution is one that

maintains a constant pH upon the addition of small amounts of either acid or base.

A strong base (closer to 14) reacts with relatively

many H+ ions.

The second number associated with each atom is the

mass number.

C-12 and C-13 atoms will have DIFFERENT

mass numbers.

The mass number expresses the sum of the

masses of the particles in an atom.

Animals have a ____________________ or a small voltage difference between the inside and outside of the cell.

membrane potential

A pH between 2 and 5 indicates a

moderately strong acid solution.

A pH of 2.56 indicates a solution whose pH lies between 2 and 5. Thus, this solution can be called a

moderately strong acid solution.

Osmolarity =

molarity X number of particles/molecule

Another method of expressing solution concentration is in terms of

molarity, or moles of solute per liter of solution.

Should the inside of the cell be positive or negative when compared with the outside of the cell?

negative

The electron has what type of charge?

negative

If an atom were to gain an electron, it would then have an overall

negative charge.

7 on the pH scale is

neutral (water)

Is water acid, base, or neutral?

neutral.

If no ions are produced then

no electricity is produced.

When surcrose, C12H22O11, is placed in water,

no ions are produced.

A solution of sucrose would be considered a

non-electrolyte because it does not produce any ions.

Normal metabolic processes add acid to the bloodstream. What effect should these acids have on the pH of the blood?

none

A permeable membrane is

nonselective.

An atom consists of an inner part, or________________, that is made up of ________________ and ________________.

nucleus protons neutrons

The protons and the neutrons are packed together in an inner core called the

nucleus.

A mole of a compound is the

number of grams of that compound equal to its molecular mass.

There are over 100 known elements. Each element has 2 numbers associated with it,

numbers that give certain facts about the structure of its atoms.

If a neuron is stimulated, then the sodium channels

open but the potassium channels remain closed.

Potassium flows

out of the cell.

Electrons are located

outside the nucleus

A moderately strong acid will have a

pH between 2-5.

The addition of a weak acid or a weak base should have little effect on the

pH.

When calculating osmolarity, remember

particles divided by molecule X molarity.

Colloids consist of very thin

particles suspended in liquid, usually water. (Colloids may also be suspended in solids and in gases).

Diffusion across a membrane is called

passive transport, because it requires no external energy.

For medical use, solutions are frequently described in terms of

percent or parts per hundred.

A proton has what type of charge?

positive

The nucleus attracts the negatively charged electrons. Therefore, the overall charge of the nucleus must be

positive.

During the undershoot phase, which channels are slow to close?

potassium

The potassium ion (K+) is the

principal cation inside animal cells (the principal INTRAcellular cation).

One example of a colloid is

protein.

The charge on the electron balances the charge on the

proton.

Therefore, the atomic number of an element indicates the number of____________in the nucleus of the atom and also the number of_______________outside the nucleus.

protons electrons

A base accepts or reacts with

protons (hydrogen ions).

The ion system pumping sodium ions out of the cell and potassium ions into the cell is called a

sodium-potassium pump.

A solution consists of a

solvent (water) and a solute (molecules dissolved in water)

hydrochloric acid

substance produced by the stomach; necessary for digestion of food

Note that nonmetals have higher electronegativities

than do metal.

A hydrogen bond is caused by

the attraction of the partially positive H of one water molecule and the partially negative charged O (more electronegative) of another water molecule.

As sodium ions flow into the cell, the potential of that cell will change from - to +;

the cell is said to be depolarized.

In general, the greater the difference in concentration on two sides of a membrane,

the greater the osmotic pressure.

Osmolarity is expressed in the

units osmoles, or osmol.

When a strong base is added to water, the pH should go

up.

Some elements reach their most stable state when they have 2 electrons in their outer (their only) energy level, which is called the

valence shell.

Osmotic pressure is

water pressure that develops as a result of osmosis.

A buffer consists of a

weak acid and a weak base.

A pH between 5 and 7 indicates a

weak acid solution.

Noncovalent bonds are

weak chemical bonds in which no electrons are shared.

The cathode will attract ions of what charge?

(+)

The anode will attract ions of what charge?

(-)

A resting cell has a

(-/+) charge inside.

The sodium ion (Na+) in the principal cation outside the animal cell

(EXTRAcellular cation)

ATP

(adenosine triphosphate) main energy source that cells use for most of their work.

If the electron has a charge of -1, then the proton would have a charge of

+1.

The log (exponent) of 10-3 is

-3.

The log of 10-7 is

-7.

Mathematically, pH =

-log H+.

The neutron has a charge of

0

The 2 electrons in the helium atom have a total of

0 daltons.

The pH range in from

0-14.

A strong acid will have a pH anywhere between

0-2.

Physiologic saline solution, 0.95% NaCl solution, contains _________ of NaCl in 100 mL of solution.

0.95 g

The maximum number of electrons in the 4th energy level is

32. (n = 4)

A proton has a mass of

1 dalton.

A 1-molar (1M) glucose solution contains

1 mole (180 g) of glucose dissolved in enough water to make 1 liter of solution.

Hydrogen, the simplest atom, contains only one proton, so the atomic number of H is

1.

If H+ = 10 -1, then pH equals

1.

A hydrogen atom has a mass of

1.01.

A 5% glucose solution contains 5 g of glucose in

100 mL of solution.

One arrow indicates

100% ionized

1 osmol =

1000 mosmol

An atom with 12 protons in the nucleus would have how many electrons outside the nucleus?

12

If the magnesium nucleus contains 12 protons, then there must be how many electrons?

12

The atom of magnesium, atomic number 12, must have nucleus containing

12 protons.

Magnesium has how many neutrons?

12.

The sodium atom (Na) has a mass number of 23 and an atomic number of 11. The number of neutrons in the nucleus of the Na atom is

12.

The 2 protons in the helium atom have a total of

2 daltons.

The first energy level can hold no more or no less than

2 electrons.

A 2% boric acid solution contains _________ of boric acid in 100 mL of solution.

2 g

For every_______sodium ions pumped out of a cell, ___________potassium ions are pumped in the cell.

3 ; 2

Note that the human body fluids have an osmolarity of approximately

300 milliosmol.

If H+ = 10-4, then pH = -log H+ = -(-4) =

4.

The helium atom has a mass number of

4.

Carbon has an atomic number of 6 and an mass number of 12, which indicates how many neutrons?

6.

The electron cloud has a negative electrical charge. What type of charge would you expect the electron to have?

A negative electrical charge, because the cloud consists of electrons.

What energy compound is required for active transport?

ATP

8-14 on the pH scale is

Basic or Alkaline (14= most basic, 8= least)

Carbon Isotopes

C-12, C-13, C-14

Acetic Acid (Vinegar)

CH3COOH

pH is the negative log of the H+.

If H+ = 10 -12, then pH equals 12.

Hydrochloric acid (HCl), is a strong acid.

It yields many H+ ions in solution.

A carbon atom (C) has 6 protons, 6 electrons, and 6 neutrons.

Its atomic number is 12.

What ion does active transport pump into the cell?

K+

A resting neuron has a higher_______________concentration inside the cell and a higher _________________concentration outside the cell.

K+ Na+

Chlorine-35

Mass number 35 Atomic No. - 17 ------ Neutrons: 18

Chlorine-37

Mass number 37 Atomic No. - 17 ------- Neutrons: 20

Cathode

Negatively charged electrode (-)

Would a solution of sucrose conduct electricity?

No

Does osmosis take place in the same direction through the membrane as diffusion of a solute?

No (opposite directions)

In a suspension, is there a solute? Why or why not?

No, the substance DOES NOT DISSOLVE IN WATER.

Many proteins are colloids. Should such proteins be able to pass through the membranes of the kidneys and be present in the urine? Should Na?

No; Yes

Anode

Positively charged electrode (+)

HCl -> H+ + Cl- (Hydrochloric acid)

Solutions of electrolytes conduct electricity because of the presence of ions:

Hydrogen bonds can also occur between the H attached to an amino group and an O that is part of a carboxyl group.

Such hydrogen bonds are present in proteins and in DNA.

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

The atomic number indicates the number of protons (each with atomic mass 1) inside the nucleus of an atom. The mass number indicates the number of protons and neutrons (each with atomic mass 1) in the nucleus.

Therefore, the number of NEUTRONS can be determined by subtracting the atomic number from the mass number.

The positive charge of the nucleus must be due to the second type of particle is contains.

This second type of particle is the proton.

Bases

accept hydrogen ions or protons.

On the pH scale, 0-6 is

acidic.

Electrolytes consist of

acids, bases, and salts

Substances that yield hydrogen ions or protons in solution are called

acids.

Atoms are electrically neutral. Therefore, an atom will contain:

an equal number of protons and electrons.

Ions attracted toward an anode are called

anions.

C-12 and C-13 atoms will have the SAME

atomic number(s).

The first number is an

atomic number.

Because hydroxide ions accept (react with) hydrogen ions, OH- ions are

bases.

A weak acid will have a pH

between 5-7.

After repolarization,

both channels are closed and active transport takes over to return the cell to its resting state.

Ions attracted toward a cathode are called

cations.

Isotopes, then, may be defined as atoms that have

different mass numbers and the same atomic numbers.

Osmosis

diffusion of water across a selectively permeable membrane.

Colloids differ from suspensions in that colloids

do not settle.

When a strong acid is added to water, the pH should go

down.

The electron has a negative electrical charge and is symbolized by

e-.

The neutron has no

electrical charge; it is neutral.

Acids, bases, and salts are called

electrolytes.

The atomic number is the number of

protons in the nucleus of the atom.

Three major elementary particles are

protons, neutrons, and electrons.

A buffer solution can "sponge up" excess H+ if added to a solution, or it can

release H+ if the H+ concentration drops. One such buffer in the body is the H2CO3/NaHCO3 system.

Remember that like electrical charges

repel each other and unlike charges attract.

Osmotic pressure will have a net result that will show a

rise in the liquid level on the sugar side (solvent side) and a drop in the liquid level on the water side.

A compound that yields ions other than hydrogen ions (H+) or hydroxide ions (OH-) is called a

salt.

A semipermeable membrane is one that is

selectively permeable.

When atoms of two nonmetals combine, the difference is the electronegativities is

small or zero and a covalent bond results.

During the undershoot phase, which channels remain closed?

sodium

The iodide ion (I-), is necessary for

the proper functioning of the thyroid gland.

Once the cell has become depolarized,

the sodium channels close and the potassium channels open.

Diffusion is the

the tendency of atoms, molecules, and ions in a liquid or air solution to move from areas of higher concentration to areas of lower concentration.

The difference in atoms' electronegativity determines

the type of bond that can form between them.

Because the extracellular and intracellular concentrations of Na+ and K+ ions are unequal in animal cells,

there must be another force acting.

The flow of potassium ions out of the cell during repolarization continues afterward because

these channels are slow to close.

The second energy level must be filled with 8 electrons before electrons can move

to the third energy level.

Colloidal dispersion's are usually________________. The _____________ through membranes.

translucent or milky white; do not pass

Acids

yeild hydrogen ions and protons.

An electron is considered to have

zero mass, or a mass of 0.

An atom with one portion in its nucleus would therefore have an overall charge of

zero.