Chemistry Basics Quiz

Balanced Chemical Equations

• A balanced chemical equation represents a chemical reaction where the number of atoms for each element on the reactants' side (left) equals the number of atoms for that element on the products' side (right).
• This principle adheres to the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction.

Arrangement of Elements in the Periodic Table

• The periodic table arranges elements based on their atomic number, which is the number of protons in their nucleus.
• Elements with similar chemical properties are grouped together in columns known as groups or families.
• Rows are called periods and represent increasing energy levels of the electrons in their atoms.

Compounds

• A compound is a pure substance formed when two or more different elements combine chemically in a fixed ratio.
• The properties of a compound are distinct and different from the individual elements that make it up.
• For example, water (H2O) is a compound formed from the elements hydrogen and oxygen.

Role of Subatomic Particles

• An atom's identity is determined by the number of protons in its nucleus.
• This number is known as the atomic number.
• While neutrons contribute to the atomic mass, they do not affect the element type.
• Electrons, located outside the nucleus, are involved in chemical bonding and determine an atom's reactivity.

Reactants and Products in Chemical Reactions

• Reactants are the substances present at the beginning of a chemical reaction, while products are the substances formed as a result of the reaction.
• During a chemical reaction, reactants are transformed into products through the rearrangement of atoms and the breaking and formation of chemical bonds.
• The chemical equation represents this transformation, conserving the total number of atoms for each element involved.