Elements and Atoms
The most basic building block of matter.
What is an atom?
A substance formed when two or more different elements are chemically combined in a set ratio.
What is a compound?
The small number written below and to the right of an element's symbol that indicates how many atoms of that element are present.
What is a subscript?
The starting substances located to the left of the yield arrow in a chemical equation.
What are reactants?
The letter "B" in the P-E-C-S-B memory aid stands for this sign of a chemical reaction, which shows gas release.
What is bubbles?
A pure substance made of only one type of atom that cannot be broken down chemically.
What is an element?
Two or more atoms chemically combined together, such as H2 or H2O.
What is a molecule?
The large number placed in front of a chemical formula that shows how many molecules of that substance are present.
What is coefficient?
The new substances formed after a chemical reaction, located to the right of the yield arrow.
What are products?
The letter "E" in P-E-C-S-B stands for this release or absorption, often seen as light or heat
What is energy?
A 1 or 2 letter abbreviation used to represent an element on the Periodic Table.
A combination of chemical symbols and numbers used to represent a substance, such as NaCl.
What is a chemical formula?
The total number of hydrogen atoms present in 3NaOH.
What is 3?
The law stating that matter cannot be created or destroyed during ordinary physical or chemical changes.
What is the law of conservations of mass and matter?
A solid that forms and settles out of a liquid mixture during a chemical reaction, represented by the "P" in P-E-C-S-B.
What is precipitate?
True or False: Elements can be broken down by both physical and chemical changes.
What is false?
True or False: A compound retains the exact same properties as the individual elements that make it up.
What is false?
The total number of atoms present in one molecule of sugar, C6H12O6
What is 24?
A representation of a chemical reaction using chemical formulas and symbols to show the relationship between reactants and products.
What is a chemical equation?
The letters "S" and "C" in the P-E-C-S-B mnemonic stand for these two observable indicators.
What are smell and color change?
Ozone ($O_3$) contains three atoms bonded together, yet it is classified as this type of pure substance because all of its atoms are identical
What is an element?
H2 is categorized as a molecule, but it is NOT considered a compound for this specific reason
What is because it contains only one type of element (or atom)?
In the expression 2H2O, this is the total count of hydrogen atoms and oxygen atoms, respectively.
What is 4 hydrogen and 2 oxygen atoms?
In the equation C6H12O6 + 6O2 \rightarrow 6CO2 + 6H2O, these formulas represent the products.
What are 6CO2 and 6H2O (carbon dioxide and water)?
The defining characteristic of a chemical reaction that sets it apart from a physical change
What is the formation of a completely new substance?