Exam 1 review questions

For the following measured numbers, the number of significant figures is indicated in parentheses. Which is correct?

0.0130 (three)

How many moles (in mol) of Kr are contained in 3.98 × 104 mg of Kr?

0.475 mol Kr

What is the energy in joules of one mole of photon of microwave radiation with a wavelength 0.122 m?

0.980 J

Determine the number of protons, neutrons, and electrons in Se if its mass number is 75.

34 protons, 41 neutrons, 34 electrons

Potassium (K) has an atomic mass of 39.10 amu and only two naturally-occurring isotopes. The K-41 isotope (40.96 amu) has a natural abundance of 6.730%. What is the mass (in amu) of the other isotope?

38.97 amu

V

frequency

Select the arrangement of electromagnetic radiation which starts with the SHORTEST wavelength and increases to LONGEST wavelength.

gamma rays, x-rays, uv rays, infrared rays, microwaves, radio

which is not a SI unit

gram

Gold has a density of 0.01932 kg/cm3. What volume (in cm3) would be occupied by a 33.3 g sample of gold? Correct!

1.72 cm^3

Oxygen is the most abundant element in both Earth's crust and the human body. The atomic masses of its three isotopes, 816𝑂𝑂(99.757%), 817𝑂𝑂(0.038%), 818𝑂𝑂, are 15.9949, 16.9991, and 17.9992 amu, respectively. What is the atomic mass of oxygen.

15.9994 amu

How many of the following units are SI base units? Second Celsius gram meter kilometer

2 (meter and second)

Calculate the wavelength, in nanometers, of the light emitted by a hydrogen atom when its electron falls from the n = 7 to the n = 4 principal energy level.

2.16 × 103 nm

Avagadro's number

6.02 x 10^23

Planck's constant

6.626 x 10^-34

The wavelength of the blue light given off by a mercury vapor street lamp is 436 nm. What is the frequency of this light in s-1?

6.88 × 1014 s-1

How many cubic inches are in 1.00 liter? (1 in = 2.54 cm, 1L = 1000 cm3)

61.0 in^3

An unknown element is composed of onlytwo isotopes, X-79, 78.9183 amuand X-81, 80.9163 amu. If the percentage of X-79 is 50.7%, what is the atomic mass of this element?

79.9 amu

How many orbitals are contained in the third principal level (n = 3) of a given atom?

9

The correct result of the molecular mass calculation for H2SO4 is_______. 4 × 15.9994 + 32.066 + 2 × 1.0079 =

98.079

mixture

A combination of two or more substances that are not chemically combined

chemical energy

A form of potential energy that is stored in chemical bonds between atoms.

homogenous mixture

A mixture in which substances are evenly distributed throughout the mixture

heterogenous mixture

A mixture in which substances are not evenly mixed

substance

A single kind of matter that is pure and has a specific set of properties.

matter

Anything that has mass and takes up space

Isotopes

Atoms of the same element that have different numbers of neutrons

groups/families

Atoms with similarproperties are arranged in vertical columns, known as

halogens

Contains nonmetals, 7 valence electrons in it's outermost energy level. Very reactive

An atom has 28 neutrons and a mass of 52 amu. What element is the atom?

Cr

the atom has: 1.Nucleus(a small core) containing −Protons: positivelycharged particles −Neutrons: neutralparticles 2.Electrons: negativelycharged and low mass particles, outside the nucleus

Earnest Rutherford's Nuclear Theory

metals

Elements that are good conductors of electric current and heat.

Nonmetals

Elements that are poor conductors of heat and electric current

Metalloids

Elements that have properties of both metals and nonmetals.

kinetic or potential

Energy is classified as either

chalcogens

Group 6A

periods

Horizontal rows on the periodic table

Which of the following statements about subatomic particles is/are TRUE? (I) Electrons make up most of the mass of an atom. (II) Neutrons and protons are found in the nucleus of an atom. (III) Protons and neutrons have charges that are opposite in sign but equal in magnitude.

II only

Which of the following statements are TRUE? I. Electrons make up most of the mass of an atom. II. Neutrons and protons are found in the nucleus of an atom. III. Protons and neutrons have charges that are opposite in sign but equal in magnitude.

II only

Which of the following statements about isotopes is/are TRUE? (I) Isotopes of the same element differ only in the number of electrons they contain. (II) Isotopes of the same element have the same mass. (III) Isotopes of the same element have the same number of protons but a different number of neutrons.

III only

h

Planck's constant

Which of these elements exhibits chemical behavior similar to that of oxygen (O)?

S

Jules

SI unit of energy

chemistry

The study of the properties of matter and how matter changes

thermal energy

The total energy of motion in the particles of a substance

groups

Vertical columns on the periodic table

wave

a disturbance that transfers energy from one place to another

SI units

a system of physical units ( SI Units ) based on the meter, kilogram, second, ampere, kelvin, candela, and mole, together with a set of prefixes to indicate multiplication or division by a power of ten.

l

angular momentum quantum number

alkali metals

any metal in Group 1A of the periodic table

average mass of isotopes

atomic mass

A modern periodic table arranges the elements in increasing

atomic number

ml

magnetic quantum number

Ephoton

hv or hc/λ

Atom

is the smallest quantity of matter that still retains properties of matter

density

mass/volume

Which of the following is a correct set of quantum numbers for an electron in a 4d orbital?

n = 4, l = 2, ml = ‒1

noble gasses

non-metals, group 18, the most non-reactive elements

Atomic number (Z) =

number of protons

electrostatic energy

potential energy that results from the interaction of charged particles

n

principal quantum number

C

speed of light

frequency formula

speed of light/wavelength

ms

spin quantum number

potential energy

stored energy that results from the position or shape of an object

The shape of an atomic orbital is associated with_________.

the angular momentum quantum number (l)

alkaline earth metals

the elements in Group 2A of the periodic table

E

the energy of a photon

molar mass

the mass in grams of one mole of a substance

atomic mass

the molar mass of an element is equal to its atomic mass

Atoms are neutral so...

the number of protons must equal the number of electrons

3.00x10^8 m/s

the speed of light in m/s

Mass number

the sum of the number of neutrons and protons in an atomic nucleus

Λ

wavelength

de Broglie wavelength

λ=h/mv