Form One Chemistry: Matter and Atomic Structure

These flashcards cover the fundamental principles of matter, physical and chemical changes, separation techniques, atomic structure, and the properties of acids and bases as detailed in the Form One Chemistry notes.

How is matter defined in chemistry?

Matter is anything that occupies space and has mass.

What is the formula for density and its typical units?

$\text{Density} = \text{Mass} \times \text{Volume}^{-1}$ (or $\text{Mass} \div \text{Volume}$). Units are typically $g/cm^3$ or $kg/m^3$.

Describe the arrangement and movement of particles in a solid.

Particles are tightly packed together in a fixed arrangement and a regular pattern; they vibrate in position but cannot change location.

How do gas particles create pressure inside a container?

Pressure is created when gas particles, which move randomly and quickly at around $500\,m/s$, collide with each other and with the sides of the container.

What is the difference between boiling and evaporation?

Boiling occurs at a specific boiling point and forms bubbles below the surface; evaporation occurs only at the surface over a range of temperatures below the boiling point.

What occurs during condensation?

A gas changes into a liquid on cooling; particles lose energy and group together when they lack the energy to bounce away after bumping into each other.

Define filtration and its components.

Used to separate an undissolved solid from a liquid. The liquid that passes through is the filtrate, and the solid remaining is the residue.

When is crystallization used and how is a saturated solution tested?

It separates a dissolved solid from a solution when the solid is more soluble in hot solvent. A solution is saturated if crystals form on a cold glass rod dipped into it.

What is the purpose of fractional distillation?

It is used to separate two or more miscible liquids (e.g., ethanol and water) by heating the mixture to the boiling point of the substance with the lowest boiling point.

How is purity assessed using melting and boiling points?

Pure substances have specific, sharp melting and boiling points, whereas mixtures melt and boil over a range of temperatures.

What is an element?

A substance made of atoms that all contain the same number of protons and cannot be split into anything simpler.

What are the three subatomic particles and where are they located?

Protons and neutrons are in the nucleus; electrons move around the nucleus in orbital paths called shells.

Define the Atomic number ($Z$) and Mass number ($A$).

Atomic number ($Z$) is the number of protons in the nucleus. Mass number ($A$) is the total number of protons and neutrons.

What is the relative atomic mass unit based on?

One unit is equal to $1/12$ the mass of a carbon-12 atom.

What are the electron shell capacities for the first 20 elements?

The first shell holds $2$ electrons, the second shell holds $8$, and the third shell holds $8$. Once the third is full, the fourth begins to fill.

How does the electronic configuration relate to the Periodic Table?

The number of occupied shells indicates the Period; the number of outer (valence) shell electrons indicates the Group (for Groups I to VII).

Why are Noble Gases (Group VIII) unreactive?

They have a full outer shell of electrons, which is a very stable configuration.

List three physical properties of metals.

They conduct heat/electricity, are malleable and ductile, and are usually lustrous (shiny) with high density.

What is the general equation for a metal reacting with cold water?

$$\text{metal} + \text{water} \rightarrow \text{metal hydroxide} + \text{hydrogen}$$

What defines the acidity of a solution when acids are added to water?

The presence of positively charged hydrogen ions ($H^+$) makes a solution acidic.

What are the products of a reaction between an acid and a metal carbonate?

A salt, carbon dioxide ($CO_2$), and water ($H_2O$).

How is the presence of the ammonium ion ($NH_4^+$) tested?

By adding an alkali and warming the substance; if ammonia gas is present, it will turn damp red litmus paper blue.

Name two synthetic indicators used in acid-alkali titrations.

Thymolphthalein and methyl orange.