Elements, Compounds, Mixtures

Question 1

Define an element

Answer 1

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

Question 2

What are three examples of elements + their symbol and use

Answer 2

• Hydrogen (H):
  
  • Used in fuel cells for clean energy.
• Oxygen (O):
  
  • Vital for respiration in living organisms.
• Carbon (C):
  
  • Key component of organic molecules.

Question 3

What are some physical properties of metals

Answer 3

Conductivity: Metals are good conductors of heat and electricity.

Density: Metals usually have high density, making them heavier for their size.

Melting and Boiling Points: Metals generally have high melting and boiling points.

Question 4

What are some physical properties of non metals

Answer 4

Appearance: Nonmetals are generally dull and lack the shiny luster typical of metals.

State at Room Temperature: Nonmetals can be gases, liquids, or solids.

Brittleness: Solid nonmetals are often brittle and break or shatter easily.

Question 5

What are some chemical properties of metals

Answer 5

Reactivity: Many metals react with acids to produce hydrogen gas.

Oxidation: Metals tend to lose electrons during chemical reactions.

Corrosion: Some metals, like iron, can corrode when exposed to moisture and oxygen.

Question 6

What are some chemical properties of non metals

Answer 6

Reactivity: Nonmetals can vary greatly in reactivity.

Electron Affinity: Nonmetals tend to gain electrons during chemical reactions.

Formation of Acids: Many nonmetals can react with oxygen to form oxides that can produce acids when dissolved in water (e.g., sulfur dioxide forms sulfurous acid).

Question 7

What does the elemental symbol H stand for?

Answer 7

Hydrogen

Question 8

What does the elemental symbol He stand for?

Answer 8

Helium

Question 9

What does the elemental symbol Li stand for?

Answer 9

Lithium

Question 10

What does the elemental symbol B stand for?

Answer 10

Boron

Question 11

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

Answer 11

As single atoms, molecules or lattices.

Question 12

Define a molecule

Answer 12

A molecule is a cluster of two or more atoms bonded together. In molecule elements, molecules are composed of all the same type of atom.

Question 13

Describe the molecular structure of some non-metallic elements,
such as nitrogen, phosphorus, sulphur and carbon.

Answer 13

Nitrogen (N2) - two nitrogen atoms tightly bound together

Phosphorous (P4) - 4 phosphorous atoms bound in a tetrahedral shape

Question 14

What do all metals exist as?

Answer 14

Crystal lattices

Question 15

Define compounds

Answer 15

Compounds are substances made up of more than one type of atom.

Question 16

Describe the difference between molecular compounds and
compound lattices

Answer 16

• Molecular Compounds: Consist of molecules where atoms are bonded covalently (Irregular structure)
• Lattice Compounds: Atoms or ions form an extended 3D lattice structure, either ionic or covalent (grid-like structure)

Question 17

Define molecular formula and give examples.

Answer 17

A molecular formula is a symbolic representation of a molecule of any substance that expresses as the actual number of atoms of each element present in one molecule.

For example, H 2 O is the molecular formula of water (two hydrogen atoms and one oxygen atom).

Question 18

define aqueous

Answer 18

Containing water

Question 19

define aqueous solution

Answer 19

Solution containing water.

Question 20

define solute

Answer 20

Can be dissolved

Question 21

define solvent

Answer 21

The one dissolving stuff.

Question 22

define mixture

Answer 22

Two or more substances physically combined.

Question 23

define solution

Answer 23

A solution is a type of mixture where a solute dissolves completely into a solvent.