YEAR 9 – Chemistry Guaranteed Success
Elements and Atomic Structure
The first 20 elements on the periodic table include hydrogen, helium, lithium, beryllium, boron, carbon,
nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine,
argon, potassium, and calcium. Atoms are the building blocks of matter and the world around us.
Atomic Components
Protons are positively charged particles that make up part of an atom. Electrons are negatively charged
particles that also compose an atom. Neutrons, on the other hand, have a neutral charge and are
another essential component of an atom.
Periodic Table
The atomic number on the periodic table represents the number of protons in an atom's nucleus.
Chemical Reactions
Exothermic reactions involve chemical changes that release heat or light. Endothermic reactions require
heat energy to occur and often release cold energy. Ionization occurs when an atom gains or loses
electrons to achieve a different charge.
Signs of Chemical Reactions
Chemical reactions can be identified by observing changes in substances when they are mixed together.
The combination of magnesium and oxygen is a classic example of combustion, which releases heat and
light.
Elements and Atomic Structure
The first 20 elements on the periodic table include hydrogen, helium, lithium, beryllium, boron, carbon,
nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine,
argon, potassium, and calcium. Atoms are the building blocks of matter and the world around us.
Atomic Components
Protons are positively charged particles that make up part of an atom. Electrons are negatively charged
particles that also compose an atom. Neutrons, on the other hand, have a neutral charge and are
another essential component of an atom.
Periodic Table
The atomic number on the periodic table represents the number of protons in an atom's nucleus.
Chemical Reactions
Exothermic reactions involve chemical changes that release heat or light. Endothermic reactions require
heat energy to occur and often release cold energy. Ionization occurs when an atom gains or loses
electrons to achieve a different charge.
Signs of Chemical Reactions
Chemical reactions can be identified by observing changes in substances when they are mixed together.
The combination of magnesium and oxygen is a classic example of combustion, which releases heat and
light.
