chemistry exam
How many carbon atoms are in sucrose? the chemical formula is C12H22O12.
12
When ammonium nitrate explodes, the products are nitrogen, oxygen, and water. When 40 grams of ammonium nitrate explode, 14 grams of nitrogen and 8 grams of oxygen form. How many grams of water form?
18 grams
Solve. (7.2 x 10^-4) / (3.6 x 10^3)
2.0 x 10^-7
The freezing point of water is 0°C, or_______ on the Kelvin scale
273.15
Solve. (4.3 x 10^4) + (1.3 x 10^4) =
5.6 x 10^4
How many valence electrons are in halogens
7
How could you distinguish an element from a compound?
A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. Compounds contain different elements in a fixed ratio arranged in a defined manner through chemical bonds.
What is the chemical symbol for silver?
Ag
Aluminum Nitrate
Al(NO3)3
Aluminum hydroxide
Al(OH)3
An atom or group of atoms with a positive or negative charge is called
An ion
A negatively charged group of atoms is called
Anion
Describe the relationship between wavelength and frequency
As the wavelength of light increases, the frequency decreases. Wavelength is the distance between the crest. Frequency is the number of waves cycles to pass a given point.
Why would carbon and silicone have similar properties
Because they are the same. And they have some similarities
What is required to break a bond between two covalently bonded atoms
Bond dissociation energy
Give an example of a halogen element
Br, I, Cl, F
What is the chemical symbol for carbon?
C
CO2S3
Cobalt (III) Sulfide
What are bonds that are in molecular compounds that form by sharing electron pairs.
Covalent bonds
Metal atoms arranged in very compact and orderly patterns
Crystalline structure
Copper(II) sulfide
CuS
Express the formula for finding density
Density= mass/volume
N2O3
Dinitrogen Trioxide
What is a basic rules governing the filling Of atomic orbitals by electrons
Electrons occupy the lowest possible energy level, and atomic orbital can hold at most two electrons, one electron occupies each of a set of overdose with equal energy before any pairing of electrons occurs
True or false. An oxygen molecule contains a triple covalent bond
False
True or false. Nonmetals lose electrons to form anions.
False
True or false. When an electron absorbs a quantum of energy, it gives off energy in the form of color.
False
Iron (II) oxide
FeO
Fluorine has a smaller atomic radius and both oxygen and chlorine because of?
Flooring has a smaller atomic radius and actually because fluorine has a larger nuclear charge and because fluorine has fewer energy levels
What is the most electronegative element on the periodic table?
Fluorine
What is the chemical symbol for hydrogen?
H
which noble gas does not have eight electrons in its highest occupied energy level?
He
Write the symbols of the noble gases
He, Ne, Ar, Kr, Xe,
Provides warmth on earth
Infrared
what studies non carbon based chemicals in rocks
Inorganic chemistry
What what is the strongest bond?
Ionic bonds
Fe2O3
Iron (III) Oxide
Atoms of an element having different numbers of neutrons are called
Isotopes
tell how electronegativity changes as you go across the periodic table from left to right. Tell how it changes as you go from top to bottom.
It decreases from left to right and increases going from top to bottom.
Why is air classified as matter?
It has mass and takes up space
Potassium nitride
K3N
Potassium Phosphate
K3PO4
Potassium phosphate
K3PO4
Write the symbols of the group 1A metals
Li, Na, K, Rb, C, Si, Fr
Explain briefly why metals are good conductors of electricity
Metal particles are held together by strong metallic bonds that have high melting and boiling points. Free electrons can move through medals because of this.
Bonds that are holding metals together
Metallic bonds
Would you expect metals or nonmetals in the same period to have higher ionization energy
Metals
Usued in the kitchen for cooking
Microwave
The melting point of a compound is 240°C. Is this compound most likely an ionic or a molecular compound?
Molecular
Nitrogen dioxide
NO2
Of Mg and Na which would have the smaller atomic radius?
Na
sodium nitrate
NaNO3
sodium sulfide
NaS
Explain why neon is monatomic but chlorine is diatomic
Neon has a complete outer electron orbitals shelf. Chlorine has one less they complete outer orbital shell
Atoms and ions with the same number of electrons are called isoelectronic. Is it possible for a cation to be isoelectronic within anion from the same period?
No
What is the chemical symbol for oxygen?
O
tetraphosphorus decaoxide
P4O10
What is the chemical symbol for lead?
Pb
Classify each of the following as physical or chemical changes. Water Boils? Salt dissolves in water? Milk turns Sour?
Physical, physical, chemical.
Reactants Na and Cl combine in a chemical reaction to form NaCl, Sodium Chloride. NaCl is called the _________ of the reaction
Product
Communication
Radio waves
Sulfur hexafluoride
SF6
Sulfur trioxide
SO3
Tin (IV) nitrite
Sn(NO2)4
Explain why NaCl in solution conducts electricity although solid NaCl will not.
Solid NaCl maintains a crystalline structure that does not have free electrons as in the lattice structure of metals. But when dissolved in water, the crystalline structure is broken down and the salt molecules become ions.
As the temperature rises, which solid will melt before mercury boils?
Sulfur
Define the term absolute zero
The lowest temperature that is theoretically possible
The electron configuration achieved by atoms when they share electrons to form covalent bond is called?
The noble gas configuration
Describe the difference between an ionic bond and a covalent bond
Their difference is structure and properties. Covalent bonds consist of pairs of electrons shared by two Atoms and binding together in a fixed orientation. An ionic bond is a bond between a cation and an anion
Used for tanning skin and growing plants
Ultraviolet light
Helps us see things
Visible light
Taking pictures of the interior of the body
X-ray
Yes or no. Based on their locations in the periodic table, would you expect carbon and silicone to have similar properties
Yes
What is the name of the element for each chemical symbol? Al Hg F S Mo Cu
aluminum mercury fluorine sulfur molybdenum
Al(ClO3)3
aluminum chlorate
Al2O3
aluminum oxide
what measures the level of lead in blood
analytical chemistry
What investigates changes that occur as food is digested in the stomache
biochemistry
Ca3(PO4)2
calcium phosphate
A positively charged ion is called
cation
List three ways that matter is meaured
count, volume, mass
a molecule consisting of two atoms
diatomic molecule
N2O4
dinitrogen tetraoxide
What colorless substance is a liquid at -30 C?
ethanol
True or false. When an electron absorbs a quantum of energy, it gives off energy in the form of color.
false
True or false. You perform an experiment and find the results do not agree with am accepted theory. You should conclude you made an error in your procedure
false
Are ice cubes in liquid water homogeneous or heterogeneous?
heterogeneous
Are mashed, unpeeled potatoes a homogeneous or a heterogeneous mixture?
heterogeneous
Is chocolate chip ice cream a homogeneous or heterogeneous mixture
heterogeneous
Is food coloring homogeneous or heterogeneous?
homogeneous
The melting point of a compound is 1240 degrees celsius. Is this compound most likely an ionic or molecular compound?
ionic
Atoms of an element having different numbers of neutrons are called what?
isotopes
PbF2
lead (II) fluoride
PbCl4
lead chloride
MgCO3
magnesium Carbonate
The law of conservation of mass means?
mass is conserved in any physical change, mass is conserved in any chemical reaction, mass is neither created or destoyed.
Which metal ions tend to have a color in solution.
metal ions with partially filled d orbitals
What colorless substance is a gas at 60 C?
neon
What studies carbon-based chemicals in coal
organic chemistry
Explains the energy transfer that occurs when it melts
physical chemistry
KCl
potassium chloride
What two physical properties could be used to separate iron filings from table salt?
put both in water and filter the resulting mixture. or you can use a magnet
In the chemical reaction Na+ Cl+--> NaCl, the substances on the left side of the equation are called ___________, and the substances on the right are called the_____________.
reactants, products
Na2CrO4
sodium chromate
SrC2O4
strontium oxalate
What substance is a solid at 7 C?
sulfur
Define electronegativity
the ability that atoms can attract electrons when the atom is a compound.
Why would we expect carbon and silicon to have similar properties?
they have the same amount of valence elctrons
Sn3(PO4)4
tin (IV) phosphate
SnS2
tin (IV) sulfide
True or False. Nonmetals gain electrons to form anions
true
Yes or No. Based on their locations in the periodic table, would you expect carbon and silicon to have similar properties.
yes
