Elements, Compounds, Mixtures

Question 1

What is an element?

Answer 1

An element is a substance that is made up of only one type of atom.

Question 2

Example of elements and uses?

Answer 2

Hydrogen is in water and water is essential for life.

Oxygen is the air we breathe and is essential for life.

Chlorine is used as a disinfectant for water.

Question 3

What are physical properties of metal?

Answer 3

Metals are malleable and ductile.
Metals are shiny
Metals are solids at room temperature
Metals are tough and strong

Question 4

What are chemical properties of metal?

Answer 4

The density of metals is usually high.
Metals form an alloy with other metals or nonmetals.
Some metals react with air and corrode.
Metals are good conductors of heat and electricity.

Question 5

What are physical properties of nonmetal?

Answer 5

Non-metals are brittle
Non-metals are dull and cannot be polished
Non-metals may be solids, liquids or gases at room temperature.
Non-metals are neither tough nor strong.

Question 6

What are chemical properties of nonmetal?

Answer 6

Nonmetals are poor conductors of heat and electricity.
Nonmetals react more with metals compared to non metals
Nonmetals usually react with other nonmetals at high temperatures.
Most nonmetals do not react with air in room temperature.

Question 7

Molecular formula for nitrogen

Answer 7

N2

Question 8

What are the 3 ways atoms can be arranged in elements?

Answer 8

Single atom: One atom, monatomic.
Molecule: Clusters of atoms.
Lattice: Large grid like structured, square structure.

Question 9

What is a molecule?

Answer 9

A molecule is a group or cluster of 2 or more atoms held together by attractive forces known as chemical bonds.

Question 10

Describe the molecular structure of nitrogen

Answer 10

(N2) - 2 nitrogen atoms bonded tightly together.

Question 11

Describe the molecular structure of phosphorus

Answer 11

(P4) - 4 phosphorus atoms in a tetrahedral shape (Pyramid shape)

Question 12

Describe the molecular structure of sulphur

Answer 12

(S8) - Under normal conditions, sulfur atoms form cyclic octatomic molecules. 8 sulphur atoms in one molecule.

Question 13

Describe the molecular structure of carbon

Answer 13

(C6) - A ring of six carbon atoms, connected by alternating double bonds.

Question 14

Are metals a crystal lattice structure?

Answer 14

All metallic elements are crystalline solids at room temperature, meaning that their molecular structure is a lattice.

Question 15

What is a compound?

Answer 15

A compound is a substance that is made up of two or more different chemical elements.

Question 16

What is a molecular formula?

Answer 16

A molecular formula is a chemical formula that gives the total number of atoms of each element present in a molecule.
E.g H20
2 hydrogen atoms, one oxygen

Question 17

Define the terms aqueous, mixture, solute, solvent, solution.

Answer 17

Aqueous: Containing water, similar to water
Mixture: A combination of two or more substances.
Solute: A dissolved substance.
Solvent: A substance that dissolves the solute.
Solution: A mixture including 2 or more substances. A mixture containing the solute and solvent.