Elements, Molecules and Compounds
The smallest unit of matter which has properties of a chemical element.
What is an atom?
These are the ingredients of a reaction; they are on the left side of the arrow.
What are reactants?
The subatomic particles (the parts of an atom.)
What are protons, neutrons, and electrons.
Matter can neither be _____________ nor ______________.
What is created, destroyed OR made, lost.
This tells the number of protons in an atom.
What is the atomic number?
Two or more atoms bonded together form this.
What is a molecule?
A process that involves the rearrangement of atoms to form new substances.
What is a chemical reaction? (law of conservation of matter/mass)
The location where most mass is found in an atom
What is the nucleus?
You burn a log and the ashes weigh less than the log. Does this violate the Law of Conservation of Matter? Why or why not?
What is no, because some matter turned into gases that escaped into the air?
This chemical formula, O₂, represents a molecule made of two oxygen atoms. Is it an element, compound, or molecule?
What is both an element and a molecule?
Water (H₂O) is an example of this kind of substance, made of more than one type of element chemically combined.
What is a compound?
The rusting of iron is an example of this kind of change.
What is a chemical change?
The charge and location of an electron.
What is negative and electron clouds?
n a chemical reaction, if you start with 20 grams of reactants, how many grams of product should you end up with?
What is 20 grams (because matter is conserved)?
These cannot be broken down into simpler substances; everything around us is made up of combinations of them.
What are elements or atoms?
This chemical formula, O₂, represents a molecule made of two oxygen atoms. Is it an element, compound, or molecule?
What is both an element and a molecule?
This is the formation of a solid from two liquids mixing, often seen as a cloudy substance.
What is a precipitate?
The charge o and locations of a neutron.
What is no charge or neutral and located in the nucleus?
List at least 3 indicators of a chemical change.
What are unexpected color changes, gas is produced (smell or bubbles or fizz), a solid is formed, bright light or temperature change, etc.
You mix two clear liquids, and a white solid forms. The container feels warmer. If you weigh everything before and after the reaction, will the total mass change?
What is no, the mass will stay the same.
Which of the following is not a compound: H₂, H₂O, or CO₂?
What is H₂, because it’s made of only one kind of atom, so it's an element and a molecule—not a compound.
This is a sign that a new substance has formed, and cannot be reversed easily.
What is a chemical change?
Valance electrons are electrons found in the outer most electron cloud they determine what about the atom
What is reactivity
(ex: how easily it will form a bond with another atom) ex: C bonding with O to form CO known as carbon monoxide
C2H6O + 3O2 → 2CO2 + 3H2O
The number of atoms on the reactant side, and the number of atoms on the product side
15 atoms reactant and 15 atoms product
The number of this can be found by looking at the coefficient in front of a chemical formula
What is a molecule?