19 questions
Two different liquids are poured together in an open container. Bubbles begin to form. After the bubbling stops, it is determined that the total weight of the two liquids is less than before they were poured together. Which best describes this observation?
Some of the atoms during the reaction escaped into the air.
Some of the atoms during the reaction were destroyed.
Some of the atoms during the reaction became heavier.
Some of the atoms during the reaction changed to a different kind of atom.
H2CO3 → H2O + CO2 How does the reaction support the Law of Conservation of Mass?
Several molecules of water are produced.
The mass of carbon atoms is reduced during the reaction
The mass of the atoms in the reactant equals the mass of the atoms in the products.
The mass of hydrogen atoms is the only thing that remains the same before and after the reaction.
Which is classified as an element?
carbon dioxide
iron
vinegar
water
Which statement is true about a chemical reaction?
The physical states of the atoms in the reactants determine the products.
Some of the atoms in the reactants will be a part of the products
The number of atoms in the reactants determines the products.
All of the atoms in the reactants will be a part of the products.
How does the concept of conservation of mass apply to chemical reactions?
The reactants and products have exactly the same atoms.
The reactants and products have exactly the same molecules.
The change in the amount of matter is equal to the change in energy.
The change in the amount of matter is only a small percentage of the total mass
Which statement best explains how the periodic table is organized?
increasing number of neutrons from left to right
increasing atomic number from left to right
decreasing number of electrons from left to righ
decreasing atomic mass number from left to right
How does a balanced chemical equation satisfy the Law of Conservation of Mass?
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.
During a chemical reaction, the total amount of matter stays the same.
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.
Max combines baking soda and vinegar in a flask. Which is the most likely reason Max should place a balloon over the mouth of the flask before he mixes the two substances?
to prevent any liquid used as a reactant from escaping during the reaction
to prevent any powder used as a reactant from escaping during the reaction
to prevent any gas formed as a product from escaping during the reaction
to prevent any liquid formed as a product from escaping during the reaction
Which best describes elements found in a column of the periodic table?
The elements have the same-size atoms.
The elements have the same atomic number.
The elements have similar chemical properties.
The elements are all found naturally in the same physical state.
How can one tell using the periodic table if 2 elements are similar chemically?
their group
their period
their atomic numbers
their atomic mass
Which of the following is an example of a compound?
copper
iron
carbon
water
Which of the following is not a compound
salt
water
sugar
nitrogen
Which correctly partners the compound with the correct formula?
NaCl - sugar
NaCl-Salt
C6H1O6- salt
none of the above
Which element is a highly reactive metal (look at the group it is in)
Lithium
oxygen
iron
argon
which element is a highly reactive nonmetal?
sodium
chlorine
copper
aluminum
Which element would be malleable, shiny and a good conductor of heat and electricity?
oxygen
sulfur
copper
nitrogen
What period is Rubidium (Rb) in?
2
3
4
5
What is the best way to remove sodium chloride (salt) from salt water?
sedimentation
condensation
evaporation
filtration