Mid Year Science Review
Chemistry, Earth History, Infectious Diseases
Periodic Table
The periodic table is a table that is organized by their atomic numbers. The periodic table shows us the symbols of the elements, atomic number and the atomic mass.
Atomic Number and Atomic Mass
The Atomic number shows the number of protons and electrons in an atom of one element.
The Atomic mass is the sum of protons and neutrons in the nucleus of an atom.
Protons, Neutrons and Electrons
The protons and the neutrons is the same number as the atomic number. The electrons is the atomic number subtracted by the atomic mass.
Groups and Periods
Groups are the numbers that is above the periodic table. The groups are vertical.
Periods are the numbers beside the periodic table. Periods are horizontal.
Law of Conservation of Mass
The law of conservation states that matter cannot be created nor destroyed, it can only be transferred from state to state.
Element
are a pure substance made up of only one type of atom and cannot be separated into simpler substances.
Compound
Compounds are combination of elements that cannot be physically separated.
Mixtures
is a combination of two or more substances that are not chemically bonded and be separated by physical means
Physical Properties
Physical properties can be observed or measured without changing the composition of matter. Physical properties are used to observe and describe matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.
Chemical Properties
A chemical property is any of a materials properties that becomes evident during a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity.
Physical changes
A physical change is any change NOT involving a change in the substance's chemical identity. Here are some examples: (1) any phase change. Moving between solid, liquid and gas involves only the amount of energy in the sample
Chemical changes
Chemical change is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms. These changes are chemical: iron rusting
Vocabulary
- Periodic Table
- Atomic Number
- Atomic Mass
- Groups
- Periods
- Law of Conservation of Mass
- Element
- Compound
- Mixtures
- Physical Properties
- Chemical Properties
- Physical Changes
- Chemical Changes