Notes

Why sugar dissolves faster in the hot water than in cold water?
Because the higher the temperature, the faster the movement of the molecules ( hot water) so it's easily spread& it become a solution (homogeneous mixture).


Why cut apples turn brown upon exposure in the air?
Because the chemical reaction on the air/enzyme on the polyphenol oxidase or tyrosinase.


Why water expands as it freezes? Because of the high temperature.

Matter - it composes of atoms, molecules, anything matters that has mass/occupy space.
Solid - fixed volume & shape.
Liquid - fixed volume, indefinite shape.
Gas - indefinite shape & volume.

Weight - measurement of mass (kabugat/kg).
mass - amount of the matter (gravity).

Pure Substances (elements & compound) - fixed composition (number id atoms), unique in some combination.

Elements - is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. It cannot be broken down into two/more pure substance. (gold, oxygen, silver, iron, elements in Periodic table)

Compound - a substance consist of 1/more different elements in definite proportions joined by chemical bonds into a molecule. The elements cannot be separated by physical means. (water, hydrogen, peroside, salt, bleach, glucose, octane, alcohol, baking soda, chalk powder)

ISOTOPES - elements with differebt atoms (weight). Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element's atomic number on the Periodic Table. For example, carbon has six protons and is atomic number 6.

The solute is the product that the solvent dissolves. A solution of salt and water, for example, has water as the solvent and salt as the solute. Oil and Water, water is also known as the “universal solvent” because it can dissolve almost any material better than any other liquid.

The solute is the substance that is being dissolved, while the solvent is the dissolving medium.

Homogeneous mixture- has a uniform composition & appearance/cannot be separated with physical substances. (sugar & water, saline solution, some alloys, alcohol, chocolate bar w/o toppings, ice candy, tea, dishwashing liquid, zonrox)

Heterogeneous Mixture - comprises 2/more substances that can be distinctly observed & even separated relatively easily. (not uniform/can be separated) (fries w/ketchup, ice cream w/toppings, cola w/ice, cake w/decoration, salt & pepper, cement w/water, etc.)