What is an atom? Atoms are building blocks. If you want to create a language, you'll need an alphabet. If you want to build molecules, you will need atoms from different elements. Elements are the alphabet in the language of molecules.
Each element is a little bit different from the rest. In English, you know that “B” is different from “C.” In chemistry, “B” is also different from “C” because boron (B) and carbon (C) are different elements with atoms that have different structures. Atoms are defined as the smallest units of matter that have the properties of an individual element.
Are there pieces of matter smaller than an atom? Sure. Atoms are made up of smaller and even smaller particles of matter. However, those smaller particles don’t have the properties of an element. The electrons in a gold (Au) atom are the same as the electrons in an atom of neon (Ne). In chemistry, we like to study atoms because the Universe revolves around the properties of elements, not necessarily the properties of an electron or proton.
For example, let’s say you have bar of gold. You know that bar is made of matter because everything is made of matter. Because it is pure gold, there are only gold atoms in the bar. If you only had one atom of gold in your hand, it would have the same properties as every other gold atom in that bar. But what if you only had one electron from a gold atom? That electron would not have the properties of gold anymore. It would just be an electron doing electron stuff. The atom is the smallest unit that has the properties of an element.
We can teach you about the general structure of an atom, but you need to study atoms from different elements to really learn how atoms work.
Common Elements
Let's work with the alphabet idea again. If you read a book, you will find words on each page. Letters make up those words. In English, we only have twenty-six letters, but we can make thousands of words. In chemistry, you are working with almost 120 elements. When you combine them, you can make millions of different molecules.
Molecules are groups of atoms in the same way that words are groups of letters. An "A" will always be an "A" no matter what word it is in. A sodium (Na) atom will always be a sodium atom no matter what molecule it is in. While atoms from different elements have different masses and structures, they are all built with the same parts. Electrons, protons, and neutronsare the basic subunits for all atoms across the Universe.
From Simple to Complex
If you want to do a little more thinking, imagine the smallest particles of matter. Super-tiny subatomic particles are used to create the parts of atoms. Protons, neutrons, and electrons can then organize to form atoms. Atoms are then used to create the molecules around us. As we just learned, there are almost 120 elements that can be found in the molecules we know. Smaller molecules can work together and build macromolecules. It just goes on. Everything you see or imagine is built from something else.
You could start really small... - Particles of matter - Atoms - Molecules - Macromolecules - Cell organelles - Cells - Tissues - Organs - Systems - Organisms - Populations - Ecosystems - Biomes - Planets - Systems with Stars - Galaxies - The Universe ...And finish really big.
Acid - An acid is a compound with a pH of less than 7 that forms hydrogen ions when dissolved in water. Acids react when coming into contact with bases and some metals to form salts.
Alkali metals - The alkali metals are the elements in the first column of the periodic table with the exception of hydrogen.
Alkaline earth metals - The alkaline earth metals are the elements in the second column of the periodic table.
Alloy - An alloy is a metallic mixture of two or more elements. Examples of alloys include brass, bronze, and steel.
Allotropes - Allotropes are different forms in which the same element can exist. For example, the element carbon can take the form of the allotrope graphite or the allotrope diamond.
Aqueous solution - Any solution where water is the solvent.
Atom - The atom is a basic unit of matter and the smallest unit of an element. It consists of a nucleus which is surrounded by a cloud of electrons.
Base - A base is a substance with a pH higher than seven. Bases are defined as donating a pair of valence electrons.
Biochemistry - The study of chemical processes as they relate to living organisms.
Bond - An attraction between atoms that forms chemical substances.
Bunsen burner - A piece of chemistry lab equipment that produces a flame used for lab experiments.
Carbon cycle - A method by which carbon is constantly moved throughout the biosphere.
Catalyst - A substance that speeds up the rate of a chemical reaction. The catalyst is not consumed in the reaction.
Chemical reaction - A process where a set of substances undergo a chemical change to form a different substance.
Compound - A chemical compound is a pure substance made up of two or more elements.
Conductor - A conductor is a material that allows the flow of energy such as heat or electricity.
Covalent bond - Covalent bonding occurs between atoms that share a pair of electrons in order to gain full outer shells.
Density - Density is the mass per unit volume of a substance.
Distillation - The process of separating mixtures by boiling a liquid and then recovering the cooled gas.
Ductile - The ability of a material to be stretched into a long wire.
Electrolysis - A process used to drive a chemical reaction by using an electrical current. It is often used to separate elements.
Electron - A particle of an atom that orbits the atom's nucleus and carries a negative charge.
Element - A pure chemical substance that is made up of one type of atom. Each atom in an element is defined by an atomic number which is the number of protons in the nucleus.
Ion - An atom or molecule which has a negative or positive charge because the number of electrons does not equal the number of protons.
Ionic bond - Ionic bonding is when an electron is traded between atoms in order to have full outer shells.
Isotopes - Isotopes are atoms from the same element that have different numbers of neutrons.
Malleable - A substance is said to be malleable if it can be pounded into a thin sheet.
Metal - A substance that is a good conductor of heat and electricity. They are generally malleable, ductile, and shiny.
Mixture - A combination of two or more substances that are not chemically combined.
Molecule - A molecule is formed when two or more atoms are joined together by a chemical bond.
Neutron - A particle in the nucleus of an atom that has no electric charge.
Noble gases - A family of elements that makes up column 18 of the periodic table. They are very stable due to their full outer electron shells.
Nucleus - The central core of an atom containing the protons and neutrons.
Oxidation - The name for the process when oxygen combines with another element to form a compound.
Periodic table - A table of the chemical elements arranged by atomic number.
PH scale - The pH measures the activity of the hydrogen ion in substances. If a substance has a pH less than 7 it is said to be acidic. If its pH is greater than 7 then it said to be basic or alkaline.
Proton - A particle within the nucleus of an atom that holds a positive charge.
Reaction - The process that occurs when two or more chemical substances are combined to form another chemical substance.
Salts - Salts are chemical compounds that are formed by the reaction of an acid and a base.
Solution - A homogeneous mixture where one substance called the solute is fully dissolved into another substance called the solvent. For example, a solution is formed when salt dissolves into water to make the solution salt water.
Valence electron - An electron in an atom that can participate in a chemical bond.
