Unit 1
Which characteristics best describe scientific thinking?
curious, open-minded, and skeptical
Which of the following statements accurately describes energy during the phase change of freezing?
Energy is released
Which answer choice correctly describes why metals are good conductors of thermal energy?
Their atoms have free-floating electrons that easily pass kinetic energy throughout the metal.
What function does adding a coefficient in a chemical equation serve?
It balances the equation, ensuring each side of the reaction has an equal number of atoms.
Which characteristic describes mixtures?
They can be separated through physical means.
What is scientific knowledge made of?
the ideas that scientists understand and can reasonably explain
According to the law of conservation of energy, which answers choice best describes the energy of the reactants in a chemical reaction?
The energy of the reactants is the same as the energy of the products
Which of the following elements are nonmetals?
carbon (C)
arsenic (As)
aluminum (Al)
helium (He)
carbon and helium
In a chemical equation, in which direction does the "yields" arrow point, and what factor does it indicate?
It points to the right, toward the products.
Which of these is true about heterogeneous mixtures?
Their parts will always separate over time.
Their parts are evenly distributed.
Their parts are often visible to the eye.
They are defined using chemical formulas.
Their parts are often visible to the eye.
Human curiosity has led to improvements in technology, which has increased scientists' ability to _[blank]_.
make observations
An ice cube is left on the kitchen counter. After some time, the ice cube melts into a small puddle of water.
According to the law of conservation of mass, how does the mass of the puddle of water compare to the mass of the original ice cube?
It contains the same amount of mass
Which of the following statements about metalloids is true?
Metalloids are rarely used for anything besides scientific experiments.
Metalloids have high conductivity at low temperatures.
Metalloids are hard like metals but easily vaporize into nonmetals.
Metalloids have properties that fall between those of metals and nonmetals.
Metalloids have properties that fall between those of metals and nonmetals.
What is a chemical reaction?
The actual, chemical transformation from one substance into another
Which type of mixture is likely to separate if it is allowed to sit still?
suspension