Grade 9 Chemistry

Where did science in Europe originate?

Greek philosophers

How long did science gradually evolve for until it exploded?

2000 yrs and exploded in the 18th century

What did Empedocles state about matter?

Matter consists of earth, air, fire, and water

What did Democritus state about matter?

Matter consists of particles called atoms that can be further broken down

How long was Empedocles model supported?

2000yrs

What did the alchemist Hennig Brandt do?

Distilled urine to form a pure substance

What did the scientist Robert Boyle do?

He discovered matter as an element - single unmingled bodies

What did Henry Cavendish do?

Isolate hydrogen

What did Daniel Rutherford do?

Isolate Nitrogen

What did Karl Wilhelm Scheele do?

Isolate chlorine

What did John Priestly do?

Isolate oxygen

Who is the founder of modern chemistry?

Antoine Lavoisier

Explain Dalton’s atomic model

• Matter is made of tiny particles called atoms

• Atoms of the same element are the same

• Atoms cannot be created or destroyed during chemical reactions

Explain JJ Thompson’s Plum Pudding Model

Atoms contain electrons embedded in positive matter, making the atom neutral overall.

Explain Ernest Rutherford’s Atomic Model

• Atoms are mostly empty space

• They have a small nucleus with protons

• Electrons move around the nucleus

• A neutral atom has the same amount of protons and electrons

What is the order of filling the first thee orbits of an atom?

2,8,8

Explain Neil Bohr’s Quantum theory

• Electrons move around the nucleus in orbits

• Orbits with low energy levels are closer to the nucleus

• Each orbit can hold only a certain number of electrons

In an atom what is each orbits quantum number?

In the first orbit n-1, in the second n-2 and so on

Where are protons and neutrons found in an atom?

In the nucleus

Rundown of protons

Positive charge, inside the nucleus, mass number of 1, discovered by Ernest Rutherford

Rundown of electrons

Negative charge, outside the nucleus, mass number of 0, discovered by JJ Thompson

Rundown of neutrons

Neutral charge, inside the nucleus, mass number of 1, discovered by James Chadwick

What is the atomic number?

Number of protons

What is mass number?

Number of protons + number of neutrons

How do you get the number of neutrons?

Mass number - atomic number

How do you get the number of protons?

Mass number - number of neutrons

What is a single column in the periodic table called?

A group or family. They contain similar properties

What are the groups or families of the periodic table?

Alkali Metals, Halogens, Nobel Gases, and Hydrogen

What is the most common element of the Alkali family?

Sodium (Na)

What is the most common element in the Halogen family?

Chlorine (Cl)

What are rows in the periodic table called?

Periods. They don’t have similar properties but they show trends

How much of the periodic table is made up of metal elements?

75%

What are the properties metals demonstrate?

Lustre (shiny), silver-gray colour, malleable, ductile, solid, conduct heat, and conduct electricty

What is the best conductor of electricity?

Silver

What are the properties of non-metals?

No lustre, brittle, insulators, and either solid or gas at room temperature

Where are metalloids found?

A staircase of elements between metals and non-metals

How much of the periodic table is metals?

75%

How much of the periodic table is non-metals?

15%

How much of the periodic table is metalloids?

6%

What is viscosity?

The ability of a material to flow

What is density?

Measure of a material’s mass per unit volume - g/cm^3

What are the three rules for abbreviations in periodic elements?

• 1-2 letters

• First letter capitalized, second letter isn’t

• Must be derived from it’s English, Greek or Latin name