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WorksheetsPeriodic table and conservation
Total questions: 35
Worksheet time: 18mins
If a student is chemically combining 4 g of hydrogen with 2 g of oxygen, what will be the mass of the product?
4g
6g
8g
10g
When 15 grams of zinc are combined with 20 grams of hydrochloric acid, two new products are created. What will be the combined weight of the products?
5 grams
15 grams
20 grams
35 grams
When vinegar and baking soda are combined, a mixture is produced, and a gas is released. Which statement is true?
The mass of the gas is equal to the mass of the vinegar and baking soda.
The mass of the gas is greater than the mass of the vinegar and baking soda
The mass of the mixture and gas is equal to the mass of the vinegar and baking soda.
The mass of the mixture and gas is greater than the mass of the vinegar and baking soda.
Which is true of mass during a chemical reaction?
Mass increases.
Mass decreases
Mass remains the same
Mass depends on the chemicals involved.
Which of these is one similarity of the elements in the first group of the periodic table?
The elements in the group have similar atomic masses.
The elements in the group have the same number of electrons
The elements in the group are very unreactive metals
The elements in the group react with oxygen in similar ways
Which ratio of reactants to products supports the law of conservation of mass?
2:1 because the mass of the reactants is halved during the reaction
1:2 because the mass of the reactants is doubled during the reaction
1:1 because the mass of the reactants before the reaction is equal to the mass of the products after the reaction
1:0 because the mass of the reactants is completely used up during the reaction so the products have no mass after the reaction
How are elements similar to those in the same group on the periodic table?
They have the same number of valence electrons
They have the same number of electrons
They have the same number of protons
They have the same atomic mass
Which statement best explains how periods on the periodic table are organized?
increasing atomic number from left to right
increasing number of neutrons from left to right
decreasing number of electrons from left to right
decreasing atomic mass number from left to right
Which pair of elements has the most similar properties?
Li and B
I and Ca
K and He
N and P
Which is true of a chemical equation?
Products and reactants must be balanced.
Subscripts must be used with all products and reactants
Energy must be included in the beginning of the reaction
Coefficients must be used with all products and reactants
Which best explains why the total mass of the product(s) would be less than the total weight of the reactant(s) after a chemical reaction?
A physical change occurred
Atoms involved in the reaction lost mass.
Precipitates were created in the new solution
Gases were released to the atmosphere
Chlorine has 7 valence electrons. With what group of elements will
chlorine most readily bond?
group 1
group 2
group 16
group 18
How does a balanced chemical equation satisfy the Law of Conservation of Mass?
During a chemical reaction, the total amount of matter stays the same.
During a chemical reaction, matter is destroyed
During a chemical reaction, one or more new substances are formed
During a chemical reaction, the total number of atoms increases
Element X reacts with element Y to form 250 g of XY. If no reactants are left over, which are most likely the amounts of X and Y in the reaction?
75 g of X and 175 g of Y
95 g of X and 115 g of Y
100 g of X and 200 g of Y
150 g of X and 300 g of Y
Elements in the periodic table of the elements are organized into columns and rows.
The columns are organized to show the
similarities of the reactivity in groups.
number of neutrons in a column
sum of atomic weights per column.
amount of radioactivity in each group.
What is the significance of metalloids in the periodic table?
They separate liquids from solids.
They separate metals from nonmetals
They combine elements and compounds.
none of the above
Which elements are most likely to react in the same manner in a chemical reaction?
elements in the same group
elements in the same period
elements with similar atomic masses
elements with similar color
If an element has no electrons to share and is stable, what family is it found in?
alkali metals
noble gases
halogens
transition metals
Why are certain elements placed into the same column on the periodic table?
They have the same number of protons in their nuclei.
They have the same number of electrons in their nuclei
They have the same number of electrons in their outer energy level.
none
In which groups did Mendeleev most likely place highly-reactive elements?
IA and VIIA
IA and VIIIA
IIA and VIIIA
IIIA and VIA
If a chemical reaction such as photosynthesis begins with 6 atoms of carbon (C), how many atoms of carbon (C) should be in the products?
12 atoms of carbon (C)
6 atoms of carbon (C)
3 atoms of carbon (C)
2 atoms of carbon (C)
When chemicals react in a closed container, which must be true?
The mass both before and after the reaction is the same.
The mass both before and after the reaction is variable.
The same number of compounds is present both before and after the reaction.
None
Substance A has a mass of 7 grams. When substance A was mixed with substance B, a new substance was formed. Which statement best describes the Law of Conservation of Mass?
The mass of substance B is equal to the mass of the product
The mass of the product is equal to the mass of the reactants
The mass of the product is less than the mass of the reactants
All of the above
The compound ammonia is composed of nitrogen and hydrogen atoms. If two atoms of nitrogen completely react with six atoms of hydrogen to form two molecules of ammonia, which best describes the number of hydrogen atoms present in the two molecules of ammonia?
two hydrogen atoms
four hydrogen atoms
six hydrogen atoms
ten hydrogen atoms
Which must be true if the number of atoms stays the same regardless of how they are arranged?
Their total mass must change
Their total mass stays the same.
An open system must have been used
An open and closed system must have been used
A chemistry teacher combines 20 grams of lemon juice with 25 grams of baking soda in a flask covered with a balloon. The flask and balloon have a combined mass of 105 grams. What is the mass of the entire setup after a reaction has occurred?
45 grams
150 grams
605 grams
50 grams
Which best supports the Law of Conservation of Mass?
Atoms can be rearranged to keep the same mass
Atoms can be destroyed to make a new substance.
Atoms can be rearranged to change their mass.
Atoms can be produced to change their mass.
What best explains the result of substances of a chemical reaction?
A new substance is produced.
The same substance is produced.
More energy is produced in the substance
No new substance is produced.
A chemistry student combines 32 grams of one chemical and an unknown amount of another chemical in a closed system. A chemical reaction occurs and the mass of the products is 114 grams. How much of the unknown chemical was used in the reaction?
32 grams
82 grams
114 grams
64 grams
What is the importance of a closed container in a chemical reaction?
to observe the mass before and after the reaction occurs
to keep any materials from interfering with the reaction
to observe the loss of mass after the reaction occurs
to observe how the reaction occurs
How many copper atoms and how many chlorine atoms are in a molecule of CuCl2?
one copper atom, one chlorine atom
one copper atom, two chlorine atoms
two copper atoms , one chlorine atom
two copper atoms , three chlorine atom
Which best describes a chemical reaction applying the law of conservation of mass?
an equation which uses energy
an equation which does not use energy
a balanced equation in which the reactants and products are equal
an unbalanced equation in which the reactants and products are unequal
One molecule of carbon dioxide (CO2) combines with one molecule of water (H2O) to make one molecule of carbonic acid. According to the Law of Conservation of Mass, how many atoms of carbon should be in the carbonic acid?
1
2
3
4
The formula for glucose is C6H12O6. If glucose is broken down by a reaction, then how many atoms of carbon should be present in the products?
1
6
12
8
Which are conserved during a chemical reaction?
mass and atoms
volume and mass
atoms and molecules
molecules and volume
