CHM 101 Flashcards
(70 cards)
What is an atom?
The smallest unit of matter that retains the properties of an element.
What are molecules?
Groups of two or more atoms bonded together.
What is an element?
A pure substance that cannot be broken down into simpler substances by chemical means.
What is a compound?
A substance formed when two or more elements are chemically bonded together.
True or False: All compounds are molecules.
True
What is the chemical formula for water?
H2O
Fill in the blank: The nucleus of an atom contains _____ and _____.
protons; neutrons
What particle has a negative charge?
Electron
True or False: Electrons are located in the nucleus of an atom.
False
What is the periodic table?
A tabular arrangement of all known chemical elements organized by atomic number and properties.
What is the atomic number of an element?
The number of protons in the nucleus of an atom.
Fill in the blank: An ionic bond is formed when electrons are _____ from one atom to another.
transferred
What is a covalent bond?
A bond formed when two atoms share one or more pairs of electrons.
What is a chemical reaction?
A process that involves the rearrangement of the molecular or ionic structure of a substance.
True or False: In a chemical reaction, the total mass of the reactants equals the total mass of the products.
True
What are reactants?
The starting substances in a chemical reaction.
What are products?
The substances formed as a result of a chemical reaction.
What is a catalyst?
A substance that increases the rate of a chemical reaction without being consumed.
Fill in the blank: The law of conservation of mass states that mass is _____ in a chemical reaction.
neither created nor destroyed
What is a mixture?
A combination of two or more substances that are not chemically bonded.
What is an example of a heterogeneous mixture?
Salad
What is an example of a homogeneous mixture?
Saltwater
True or False: All mixtures can be separated by physical means.
True
What is a solution?
A homogeneous mixture where one substance is dissolved in another.