Chemical and Physical Changes in Science

Study Notes

Chemical Change

Involves an energy change (heat or temperature change).
May produce a change in smell.
Can often be reversed (undone).
Results in the formation of a new substance.
May exhibit a change in color.

Physical Change

Can be reversed (undone).
Does not create new substances.
May involve a change in size.

Solutions

Mixtures of multiple components, often indistinguishable.
Example: Coke contains various substances that are not visually separable.

Chemical Mixtures

Mixtures of components that are easily visible.
Example: A chicken pizza shows separate components such as chicken, cheese, and bread.

Density

Density (D) = Mass (M) / Volume (V).

Isotopes

(No specific detail provided regarding isotopes).

Covalent Bonds

Form between two nonmetals.
Involve the sharing of electrons.

Ionic Bonds

Occur between a metal and a nonmetal.
Involve the transfer of electrons (metal loses, nonmetal gains).

Compounds

Made from two or more different elements joined together.
Examples: H₂O, HCl.
Use prefixes (e.g., dioxide, trihydrogen) only when both elements are nonmetals; otherwise, use standard element names.

Formulas

Represent elements and their bonds.
Show electron sharing or transfer.
Use dots to visually represent electrons involved in bonding.

Diatomic Molecules

Seven elements naturally exist as diatomic molecules.
Memorization trick: "Have No Fear Of Ice Cold Beer" (H₂, N₂, F₂, O₂, I₂, Cl₂, Br₂).

Description

This quiz covers key concepts related to chemical and physical changes, including energy changes, properties of mixtures, and bonding types. Test your understanding of density, covalent and ionic bonds, and how these concepts apply to everyday substances. Perfect for students in chemistry classes.