physical science semester test
Balance the following equation to demonstrate the conservation of atoms in a reaction. Choose the answer which provides the correct coefficients for each reactant and product._____ Fe + _____ O2 _____ Fe2O3
(4, 3, 2)
The Avogadro number is equal to:
-One mole of a substance. -6.02 ´ 1023 molecules. -the number of atoms in the atomic mass of an element, when the mass is expressed in grams.
Lithium and oxygen combine to form a compound called lithium oxide. Lithium (Li) has an oxidation number of +1 and oxygen (O) has an oxidation number of -2.What is the total of the oxidation numbers for all the atoms in lithium oxide? -2
0
The mass of an electron is about:
1800 times lighter than a proton.
An atom contains 11 electrons. If a 12th electron were added to the atom, the energy level into which it would be placed is energy level:
3
How many energy levels are filled in a krypton atom?
4
A common isotope of Carbon has an atomic number of 6 and a mass number of 13. How many neutrons are in an atom of this isotope?
7
Bonding between atoms produces an outermost energy level for each atom filled with:
8 electrons
In the chemical equation, 2HCl + Ca(OH)2 CaCl2 + 2H2O, the number of atoms of reactants is:9
9
The general equation representing an addition reaction is:
A + B=AB
Which of the following is evidence that a chemical change has occurred?
A material changes color from blue to red.
The general equation representing a double replacement reaction is:
AB + CD=AD + CB
Which of the following is a TRUE statement about atoms?
All atoms of the same element have the same number of electrons and protons, but may have different numbers of neutrons.
Of the following statements, the one which is ALWAYS TRUE is:
All lithium atoms contain the same number of protons.
Which of the following is NOT a member of the noble gas family?
Be
Of the following, which most likely involves a chemical reaction?
Boiling water turns a fresh egg into a hard-boiled egg.
Lithium and oxygen combine to form a compound called lithium oxide. Lithium (Li) has an oxidation number of +1 and oxygen (O) has an oxidation number of -2.
C
Answer the following questions about the chemical reaction for the combustion of methane gas:CH4 + O2 CO2 + H2OIdentify the reactants in the combustion of methane.
CH4 and O2
According to Table 17-1, which of the following substances has a formula mass of approximately 44 amu?
CO2
____ are energy-rich compounds, such as starch, glucose, and sucrose.
Carbohydrates
What is the fundamental property of matter that can either be positive or negative?
Charge
What is the whole number placed in front of a molecular formula in a chemical equation called?
Coefficient
The balanced equation for the reaction between iron sulfide and water is best represented by:
Fe2S3 + 6H2O 2Fe(OH)3 + 3H2S
Which of the following is an example of a chemical property of a substance?
Forms molecules with hydrogen
Which type of radioactivity in Figure 14-1A leaves the atomic number unchanged?
Gamma decay
Which of the following is a metalloid in the carbon family?
Ge
In the periodic table notation below, what information does the number 40.08 tell you?
It is the atomic mass.
If a fat is completely saturated, what can you tell about it?
Its carbon atoms are surrounded by as many hydrogen atoms as possible.
What would the chemical formula be for a molecule made up of potassium (K1+) and oxygen (O 2-)?
K2O
In which directions on the periodic table do the atomic masses of elements increase?
Left to right and top to bottom
Which statement best explains why atoms form chemical bonds with other atoms?
Most atoms are unstable unless they are combined with other atoms.
An atom absorbs energy as its electrons:
Move from a low energy level to a high energy level
Answer the following questions about the chemical reaction for the combustion of methane gas:CH4 + O2 CO2 + H2OIs the chemical reaction for the combustion of methane balanced? If not, select the correct equation from the ones listed below.
No, this is balanced: CH4 + 2O2 CO2 + 2H2O
What do we call the tiny core at the center of an atom, containing most of the atom's mass and all of its positive charge?
Nucleus
____ are made from simpler molecules called amino acids.
Proteins
Classify the following reaction: 3CuSO4 + 2Al Al2(SO4)3 + 3Cu
Single-displacement
The diagram below represents information that can be found on the periodic table for the element helium.
The atomic mass of a helium atom is indicated by the arrow at:
Which of the following is true of a limiting reactant?
The limiting reactant is used up first.
Why don't all the electrons in an atom fall to the lowest energy level?
The lowest energy level can only hold 2 electrons.
Which of the following statements about two isotopes of the same element is FALSE?
The number of protons might be different between the two isotopes.
What do Zr, Mo, Tc and Ag have in common?
They are all transition metals from period 5
Which of the following is true for valence electrons?
Valence electrons may be lost or gained by an atom when bonding occurs with another atom.
Which of the following is NOT a carbon compound found in living things?
Water
Do any of the atom diagrams below represent atoms of the same element?
Yes, atom A and atom C are the same element.
Nuclear reactions might be considered better than chemical reactions for producing usable heat energy because:
a small amount of material can be used to produce large amounts of energy.
When an atom gains or loses electrons, it has an electrical charge. It is known as:
an ion.
When a chemical change occurs:
atoms are rearranged, the law of conservation of mass is always obeyed, the chemical properties of new substances are different from the ones you started with
Ionic bonds form:
between oppositely charged atoms
Transferring or sharing electrons between atoms forms:
bonds
All of the following are characteristics of metals EXCEPT:
brittle
What do organic chemists study?
carbon compounds
The carbohydrate, ____, is used by plants to give their structure strength.
cellulose
The general name for chemical reactions combining oxygen with other reactants to release large amounts of energy in the form of heat and light is:
combustion.
Characteristics of non-metals include all of the following EXCEPT:
ductile.
Materials that allow electricity to flow through easily are known as:
electrical conductors.
A particle with zero charge found in the nucleus of an atom is called a(n):
electron
British physicist J. J. Thomson was the first to identify the:
electron
An atom contains ____ in various energy levels.
electrons
Steel can be described as all of the following EXCEPT a(n):
element.
A period's number on the periodic table corresponds to the number of:
energy levels of the atoms in the period.
Electrons with higher energy are located:
farther from the nucleus of the atom.
The sum of the atomic mass values of the atoms in a chemical formula is known as the:
formula mass.
In the reaction, 2H2(g) + O2(g) mc009-1.jpg 2H2O(l), the phase of matter in which the reactants appear is:
gas
The vertical columns of the periodic table are called:
groups
The noble gases such as helium and xenon do not form chemical bonds with other elements because they:
have completely filled energy levels.
Atoms with the same atomic number but different atomic mass are called:
isotopes
Atoms of a particular element that have different numbers of neutrons are called:
isotopes.
The Mg atom becomes the ion, Mg2+, when it:
loses 2 electrons
Sodium forms an ionic bond with chlorine when sodium ____ an electron and chlorine ____ an electron.
loses, gains
The mass of an atom is determined mainly by the:
mass of the neutrons and protons.
The element that is shiny in appearance, quite dense and liquid at room temperature is:
mercury
Most of the elements in the periodic table can be described as:
metals
Compared to protons, electrons have:
much smaller mass and opposite charge.
Protons and neutrons are found grouped together in the:
nucleus
The most abundant element in Earth's crust is:
oxygen
S is a member of which family
oxygen family
A way of organizing the elements based on their chemical properties is the:
periodic table.
Horizontal rows on the periodic table are called:
periods
Evidence for a chemical change includes all of the following EXCEPT:
phase change.
An element essential to the manufacture of DNA and glow-in-the-dark plastic is:
phosphorus
When you eat an apple, the process of digestion involves chewing and food being exposed to gastric juices. Which answer best describes change(s) involved?
physical and chemical change.
A series of addition reactions taking place to produce large molecules are called:
polymerization.
A solid that forms and is insoluble in the reaction mixture is called a:
precipitate.
The amount of product you expect from a chemical reaction is called the:
predicted yield.
A general name for ALL substances created in a chemical reaction is:
product
An atomic mass unit is the approximate mass of a single:
proton
The ____ is one kind of particle that makes up the atom and carries a positive charge.
proton
Most non-metals on the periodic table are located on the:
right
An example of a metalloid, elements with properties between metals and non-metals, is
silicon
Elements used to make semiconductors for computers include germanium and:
silicon
Which of the following compounds is NOT organic?
sulfuric acid
Atomic number is:
the number of protons in an atom.
The principle of conservation of atoms is satisfied in a chemical equation when:
the reactant side has the same number of each type of atom as the product side.
The second row of the periodic table has 8 elements because:
the second energy level can hold 8 electrons.
Protons and neutrons in the nucleus are held together by:
the strong nuclear force.
When an unstable isotope gives off a kind of radioactive decay known as an alpha particle, it is giving off:
two protons and two neutrons.
When an unstable isotope undergoes alpha decay, it gives off:
two protons and two neutrons.
Which of the following is TRUE? Covalent bonding occurs:
when electrons are shared between two atoms.
The charge on a complete atom is equal to:
zero
