Chemistry midterm
What is the charge of a cation?
a positive charge
If a material contains three elements joined in a fixed proportion, it is a(an)
compound
compounds consisting entirely of nonmetals are
covalent
at least one pair of electrons is shared between atoms forming a
covalent bond
With significant figures, you count from the left when the number is a ______ and from the right when it is a _______
decimal; whole number
proper name for N2O5
dinitrogen pentoxide
P2S3
diphosphorus trisulfide
Which subatomic particle plays the greatest part in determining the properties of an element?
electron
charge of -1
electron
the polarity of a covalent bond is determined by the difference in ___ of the atoms forming the bond
electronegativity
in a polar covalent bond
electrons are not shared equally
the type pf formula that shows the ratios or relative numbers of each type atom present in a compound is a
empirical formula
The most important rule in lab safety is to?
follow instructions
The unit of measure for density is
gm/cm^3
elements with similar properties aligned in vertical columns are called
groups
Salt water is what kind of mixture
homogeneous
A mixture that appears to contain only one substance is a(an
homogeneous mixture
Give an example of a homogeneous mixture and a heterogeneous mixture.
homogeneous- salt water heterogeneous- salad
neutron is located in __ and have a charge of __
inside the nucleus\0
bond where electrons are transferred to form ions that combine
ionic
what type of compounds do metals and nonmetals tend to form
ionic compounds
What is the energy required to remove an electron from an atom in the gaseous state called?
ionization energy
what happens to matter during a chemical reaction
it is neither destroyed nor created
how does the atomic radius change when moving left to right across a period
it tends to decrease
how does atomic radius change from top to bottom in a group in the periodic table
it tends to increase
An example of an SI basic unit is a
kilogram
What is the SI unit of mass?
kilogram
Which state of matter is characterized by having an indefinite shape, but a definite volume?
liquid
what element in the second period has the largest atomic radius
lithium
name of the binary ionic compound of Fluorine with Lithium
lithium fluoride
Which of the following elements is in the same period as phosphorus
magneisium
Write out the Law of Conservation of Mass
mass neither created or destroyed
The sum of the protons and neutrons in an atom equals the ____.
mass number
majority of the elements are
metals
type of formula where the exact numbers of each type of atom present are given
molecular formula
All atoms are ____.
neutral, with the number of protons equaling the number of electrons
The atomic number of an element is the total number of which particles in the nucleus?
neutrons
[Ar}4s^2
noble gas core, principle energy level, sub-level, number of electrons in the suborbital
the elements with the highest inization energies are the
noble gases
element that is a poor conductor of electricity is a
nonmetal`
All atoms of the same element have the same ____
number of protons
Isotopes of the same element have different ____
numbers of neutrons
identify whether the following is a physical or chemical change alcohol evaporating baking a cake leaves changing color butter melting wood rotting
p c c p c
Three different people weigh a standard mass of 2.00 g on the same balance. Each person obtains a reading of 7.32 g for the mass of the standard. These results imply that the balance that was used is ____
precise
each period in the periodic table corresponds to a
principle energy level
located inside the nucleus with a charge of +1`
proton
The atomic number of an element is the total number of which particles in the nucleus
protons
Compounds are what kind of substances
pure
NaNO3
sodium nitrate
What two states of matter occupy a definite volume?
solids; liquids
When an iron nail is ground into powder, its mass ____
stays the same
H2SO4
sulfuric acid
The nucleus of an atom is ____
the central core and is composed of protons and neutrons
compare the relative size of an ion to its neutral atom
the radius of an anion is greater than the radius of its neutral atom
there are exceptions to the octet rule T or F
true
the elements in a group have similar properties because they have the same number of
valance electrons
ZnO
zinc oxide
how many protons are present in neutral atoms of an element with an atomic number of 24
24 protons and electrons
Absolute zero corresponds to
0 k
Which of the following measurements contains two significant figures? 0.000400 0.00404 0.00044 0.004040
0.00044
What is the density of an object having a mass of 8.0 g and a volume of 25 cm^3
0.32 g/cm^3
express 1,360, 000, 000 gm in scientific notation
1.36 gm^9
express 0.000000015 cm in scientific notation
1.5 cm^-8
If 1 gallon = 3.785 liters, how many gallons are in 50 liters
13.2 gallons
dioxide indicates
2 oxygen atoms
In medieval Britain, property was often measured in units such as fardells, nookes, yards, and hides. Using the following conversions, calculate the number of fardells in eight hides. 2 fardells = 1 nooke 4 nookes = 1 yard 4 yards = 1 hide
256 fardells
how many types of chemical bonds are there
3
what is the maximum number of multiple covalent bonds possible
3
Which of the following measurements is the most accurate? 3.1000 3.10000 3.12222 3.000000
3.000000
alpha radiation symbol
4 2 (fish symbol)
How many kilometers are in 26 miles? (1 kilometer = 0.6214 miles)
41.8 km
How many protons, electrons, and neutrons does an atom with atomic number 50 and mass number 125 contain?
50 protons, 50 electrons, 75 neutrons
How many significant figures are in the following measurements 187.032 0.0601 1.30 620
6 3 3 2
An electric current is passed through a 68.3 gram sample of water to separate it into its component parts. If 7.59 grams of hydrogen gas is released, how much oxygen is produced?
60.71 grams
An element has an atomic number of 76. The number of protons and electrons in a neutral atom of the element are ____
76 protons and 76 electrons
group of elements known as noble gases
8A
What happens at absolute zero?
All atomic and molecular motion stops.
larger ionization energy Be or Ba
Be
Who said "there are two types of electric charge: positive and negative"
Benjamin Franklin
carbonate ion
CO3^-2
larger atomic radius Ca or Ca^2+
Ca
"All matter is composed of atoms which are too small to be seen."
Democritus
A substance that is made up of only one kind of atom is a(an)
Element
"Discoverer of the nucleus"
Ernest Rutherford
The metric prefix centi means one thousandth, or 0.001.
False, centi means one hundred, or 0.01
The gram is the SI base unit for measuring mass.
False; kilogram
True/ False? The safety symbol showing a flame should remind you to secure all loose equipment
False; reminds you that a flame is present so tie hair back
Why is the second ionization energy greater than the first ionization energy?
It is more difficult to remove a second electron from an atom.
"Atoms form chemical compounds by combining in fixed ratios."
John Dalton
Suggested that atom structure is related to electric charge.
Michael Faraday
nitrate ion
NO2-
larger atomic radius N or N^-3
N^-3
does not contain a molecule
NaCl
hydroxide ion
OH-
how many protons, neutrons, and electrons are present in ^91 4+ 40 Zr
P-40, N-51 and E-36
sulfate ion
SO4^-2
The meter is the SI base unit for measuring length
True
There are 1,000,000 watts in 1 megawatt.
True
larger ionization energy K or V
V
The closeness of a measurement to its true value is a measure of its
accuracy
A measurement that is very close to the standard accepted value is said to be
accurate
The Law of Conservation of Energy is
always true
factor that contributes to the increase of ionization energy from left to right across the period
an increase in the number of protons
Both homogeneous and heterogeneous mixtures
are blends of two or more substances
An example of a derived quantity is
area
The smallest particle of an element that retains the properties of that element is a(n) ____
atom
The properties of elements reoccur periodically when the elements are arranged in order of increasing
atomic number.
Which of the following numbers is not written correctly in scientific notation? a. 4.7 x 10 b. 6.23 x 10 c. 76.4 x 10 d. 3.56 x 10
c. 76.4 x 10
Burning a piece of toast is an example of a
chemical change
Which of the following elements has the smallest atomic radius?
chlorine
