Physics and Chemistry Constants: Avogadro's Number, Speed of Light, and Planck's Constant

Avogadro's number

6.022 x 10^23, number of particles in a mole.

Speed of light (c)

3.00 x 10^8 m/s

Planck's constant (h)

6.626 x 10^-34 J·s, relates energy and frequency.

Longer wavelength

lower frequency, lower energy

Shorter wavelength

higher frequency, higher energy

The shorter the wavelength, the ________ the energy

higher

The longer the wavelength, the _____ the energy

lower

The longer the wavelength the _________ the frequency.

lower

The shorter the wavelength the _________ the frequency.

higher

E=

hv or hc/λ

λ=

hc/E

v=

c/λ

2v=

c

cations

positively charged ions

anions

negatively charged ions

Ions

positively and negatively charged atoms

Nuclides

Any particular isotope of an element

Isotopes

Atoms of the same element with different numbers of neutrons

mass number (atomic mass) (A)

number of protons plus the number of neutrons in an atom of an element

atomic number (Z)

the number of protons in the nucleus of an atom, equal to the number of electrons around the nucleus

Radioactivity

The process in which some substances spontaneously emit radiation

sig figs in addition and subtraction

line decimal points up, round final answer up to lowest decimal place value given

sig figs in multiplication and division

Multiply or divide the number

2) Determine the number of sig figs in each of the original numbers

3) Round the final answer to the same number of sig figs as the original number with the fewest significant figures

how to count sig figs

-non zeros always count

-middle zeros always count

- leading zeros never count

-count if there is a decimal

Precision

a measure of how close a series of measurements are to one another

Accuracy

refers to how close a measured value is to an accepted value

Water freezes

0 C, 32 F, 273 K

Water boils

100 C, 212 F, 373 K

Abs. 0

-273 C, -459 F, 0K

Heat (q)

Energy that transfers from one object to another because of a temperature difference between the objects

Work (w)

the energy transferred when an object is moved by a force

Energy (E)

The ability to do work or cause change (E=q+w)

Matter

Anything that has mass and takes up space, can be a solid, liquid, or gas

extensive properties

depend on the amount of matter that is present

intensive properties

a physical property that remains the same no matter how much of a substance is present

Law

a generally observed natural phenomenon

Theory

a general explanation of a natural phenomenon

experiments

a test of a hypothesis or a theory

hypothesis

A testable prediction, often implied by a theory