Chemistry Final
A change of state is a physical change because...!
...
Which of the following is not a physical change?!
...
How many double bonds does a molecule of carbon dioxide have?
1
In this molecule, the two carbon atoms share...
1 electron
The atomic number of hydrogen is1. The nucleus of the isotope hydrogen-2 contains
1 proton and 1 neutron
The atomic number of sodium is 11. The nucleus of every sodium atom contains...
11 protons
The most reactive nonmetals are locate in Group...
17
New substances proceeded in a chemical reaction are called?
Products
Which organic molecules does your body use to build and repair body parts and to regulate cell activities?
Proteins
Which particles in an atom account for nearly all atoms mass?
Protons and neutrons
A student is identifying an unknown substance based on its properties. The student has found that the substance can conduct electric current only at high temperatures, not at low periodic table is the probable location of the element making up this substance?
along the zigzag line
The building blocks of proteins are...
amino acids
An alcohol is a substituted hydrocarbon that contains one or more
amino groups
Several campers sitting around a campfire discuss the chemical reaction that occurs when wood burns. They know that this reaction is...
an exothermic reaction
In liquid water, the water molecules...
are packed close together but are able to collide with and move past one another.
An element located in Group 16 of the periodic table is either a ...
nonmetal or a semimetal
The building blocks of nucleic acids are
nucleotides
isotopes of the same element differ by each other by their
number of neutrons
Carbon-12,carbon-13,and,carbon-14 are three isotopes of carbon. The atoms of theses isotopes have...
the same atomic number
The melting point of a substance is the temperature at which...
the substance changes from a solid to liquid
According to the principle of the conservation of matter, in any chemical reaction...
the total number atoms stays the same
Metals are good electrical conductors because...
the valence electrons are free to move from atom to atom
Where in the periodic table are metals found?
to the left of the zig zag line and in the two rows below the main table
Which of the following locations in the periodic table would have the least massive atom?
top left
The parts of a mixture can be separated by...
using the physical properties of its parts
Elements within the same group or family tend to have similar chemical properties because these elements have the same number of...
valence electrons
An exothermic reaction requires activation energy to ...
get the reaction started
2K+₋H₂O→2KOH+H₂ This chemical equation represents the chemical reaction between potassium and water. Which coefficient for water (H₂O) will correctly balance the equation?
2
How many atoms of oxygen are in a molecule of CO₂
2
₋Cu₂O+₋C→₋Cu+₋CO₂ Which set of coefficients placed in the blanks above will balance the chemical equation.
2,1,4,1
What is the atomic number of copper?
29
In which chemical equation below are both oxygen (O₂) and hydrogen (H₂) reactants?
2H₂+O₂→2H₂O
How many protons does an atom of krypton have?
36
How many electrons does a carbon atom have available to form chemical bonds?
4
A student in using a pH meter to find the pH of an unknown substance. If this substance is neutral, it pH will most likely be...
7
Which is the atomic mass of krypton?
83.80
#7 pg. 104
ANSWER:D
What is the chemical symbol for silver?
Ag
Give a description that describes an atom..
An atom is mostly empty space, with a tiny, dense nucleus.
Which chemical symbols best identifies the elements that make up the molecules in living organisms.
C,H,N,O,P,S
Carbon based molecules have a wide range of chemical properties because they...
Can form many different shapes.
Which change in state involves a decrease in a molecular motion
Condensation
The atoms in a molecule of water are joined by..
Covalent bonds
What is the chemical equation is a balanced equation for the burning of butane (C₄H₈)?
C₄H₈+6O₂→4CO₂+4H₂O
Which statement best describes the molecule shown in the diagram?
Each hydrogen atom shares one pair of electrons with the nitrogen atom.
Which particles of an atom move around the nucleus, forming a cloud like region of negative charge?
Electrons
When new chemical bonds form...
Energy released
In which state of matter do atoms and molecules have the most freedom of motion?
Gas
In which state of matter do the particles of the substance have the most energy?
Gas
Which group in the periodic table does the element calcium belong to ?
Group 2
Most of the elements in the periodic table are...
Metals
Which chemical formula does not represent an organic compound...
NH₃
What do atoms of the reactant rearrange to form?
New Molecules
The three particles that make up an atom are...
Protons,Neutrons,and Electrons
What happened if the substance gained enough energy so that it melted completely?
The particles would spread out into a layer that fills the bottom of the container
A student mixes together water and salt in a beaker until the salt completely dissolves , then sets the beaker aside after several days, the student return to see only a white solid in the beaker.What describes the scenario best?
The water evaporated from the solution, leaving the salt behind.
How does a container with gas inside look?
They move quickly occasionally bumping into each other.
The diagrams represent matter in three different states. The particles in State A (solid molecules)?
They vibrate in there position.
Which organic compound contains one or more hydroxyl groups?
Unsaturated hydrocarbon
IN which process do the particles in a liquid gain enough energy to move independently, forming a gas?
Vaporization
Why do living organisms need water to survive?
Water serves as a helper molecule in a variety of chemical reactions.
The diagram represents...
a molecule with two covalent bonds.
Two atoms with different atomic numbers are...
atoms of different elements
Carbon-14 is a radioactive isotope. When a carbon-14 atom decays, a neutron inside the nucleus, while the high energy electron is released from the nucleus. as a result of this process, the carbon-14 atom...
becomes an isotope a different element
In general, solids nonmetals are...
brittle and dull
Which of the following properties is not a property of metals?
brittleness
An organic compounds is a compound that contains the element..
calcium
The reactants of a chemical reaction have
chemical properties different from products
In a liquid the particles...
collide with and move past one another
A substance made of two or more elements chemically combined in a set ratio is a...
compound
An ionic compound forms a solid with an orderly, three-dimensional pattern called a...
crystal
You are given a sample of an unknown metal. Which property would best help you to identify the metal
density
What kind of molecule is it if it is repeated over and over?
diatomic molecule
What kind of bond between the two carbon atoms does this structural formula show?
double
The change in state form a liquid a gas required energy because...
energy causes the particles of a liquid to move faster and faster until the substance becomes a gas
Burning wood is an exothermic reaction because...
energy is released
A student has measured the mass of a sample of baking soda and a sample of vinegar before mixing them together. After mixing the two samples together, the student should find that the mass of the products is...
equal to combined mass of the baking soda and vinegar.
Which is not a characteristic of a molecular compound ?
hard brittle solids at room temperature
A solid substance is one that...
has a definite volume
The atoms of substances that are good electrical conductors \...
have freely moving electrons
Thermal conductivity refers to the ability of substance to conduct...
heat
What has the highest concentration of hydrogen ions (H⁺)
hydrochloric acid (pH value is 0)
When an acid is mixed with water...
hydrogen ions form
When water boils, it changes form a liquid gas. During this change the ,molecular motion of the water molecules...
increases
Which of the following best describes the elements located in the far right group of the periodic table
inert gases
Which typeof chemical bond forms as a result of the attraction between positive and negative ions?
ionic bond
the diagram illustrates the structure of a solid...
ionic compound
Which substance form so;ids by building up repeating patterns of oppositely charged ions?
ionic compounds
In a chemical reaction, the number of a reactant number...
is equal to the number of product atoms.
Compared to metals, solid nonmetals tend to be
less dense
Which state of matter has definite volume but no shape of its own...
liquid
What process changes between particles liquid to gas?
melting
The distance between particles in a gas is...
much greater than the distance between particles in a liquid
Which of the following is a characteristic of a base?
pH higher than 7
A large molecule made of a chain of many smaller molecules bonded together is called...
polymer
Which elements combine to form the compound represented by the formula KCI?
potassium and chlorine
The diagram represents an organic molecules that determines the difference among living organisms. The molecule is a...
protein
The chemical equation shows how ethene (C₂H₄) combines with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O) . The equation represents a chemical change because the...
reactant atoms rearranged to form different combinations in the products
According to principle of the conservation of matter...
reactants have the same mass as the products.
Which evidence that a chemical reaction might have occurred?
release of energy
Ionic compounds form solids by building up...
repeating patterns of ions
Elements that have some properties of metals but also some properties of nonmetals are classified as...
semimetals
Carbon atoms form covalent bonds with each other atoms. In a covalent bond, electrons are...
shared
In which state of matter do the particles of a substance vibrate vibrate while being closely locked in position?
solid
Which of the following is an example of a complex carbohydrate
starch
An atoms valence electrons are those electrons...
that have the highest energy level
An ionic bond is...
the chemical bond formed by the attraction between positive and negative ions.
The melting temperature and hardness of an element are related to...
the forces that hold the atoms together
A student mixes together iron filings and sand, then removes the iron filings form the mixture with a magnet. Making a mixture is a physical change because...
the original parts of the mixture can be separated without being changed.
When does a graph represent an exothermic reaction?
the product has less energy than the reactants
In an endothermic reaction...
the products have more energy than the reactants
