Atomic nucleus and Isotope
The atomic nucleus is the central part of the atom.The Nucleus is the largest part of the atom.Two elements that contain the same amount of protons and different number of neutrons in the nucleus
A valence electron is an electron that is associated with an atom, and that can participate in the formation of a chemical bond. Valence electrons are in the outer shell.
Ionic, Covalent, And Hydrocarbon Compounds
An ionic bond is the bonding between a non-metal and a metal.A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. A hydrocarbon is an organic compoundconsisting entirely of hydrogen and carbon.
Dmitri Mendeleev made the first one and ordered it by atomic mass. The present one was made by Henry Moseley it is ordered by atomic number. The periodic is the repetition of physical and chemical properties. it is sorted into groups and periods, groups are the columns and the periods are the rows.
Chemical and physical
A chemical reaction occurs when a reaction produces a new product. A physical reaction occurs when the substance is the same after the reaction. A piece of wood burning would be a chemical reaction and ice melting would be a physical because its still H2O.
States of Matter
The three states of matter are solids, gasses, and liquids. Solids have a fixed volume and shape and little free space between particles. Liquids have no fixed shape have medium speed and medium space. Gasses have no fixed shaped have the highest speed energy and space.
Conservation of matter
The law of conservation of matter says that matter can not be created or destroyed. There are two types of reactions that i previously explained, chemical and physical.
Acids and bases
You tell if something is an acid or base in a few different ways. You can test the test if its bitter its most likely a base and if its sour its most likely a acid. Also you can use the pH scale. the base is from 1-14, if the substance is less than seven its an acid and more is a base. Also, bases receive hydrogen atoms while the acids are the donors.
Energy in reactions
Reactions in which energy is released are exothermic reactions, while those that take in eat energy are exothermic.
Metric sytem conversions
kilo- hecto- deka- [base] deci- centi- milli- is the conversion scale. you can remember it by King Henry Died Baking Dark Chocolate Muffins. You just need to take your unit and move the decimal how ever many places it takes you to move to the right unit on the scale.
Stoichiometry uses the law of conservation of matter where the total mass of the reactants equals the total mass of the products.
2H2 + O2 --> 2H2O
you need two hydrogen molecules for every one oxygen molecule