Elements, Compounds, Mixtures Flashcards
Define an element
An element is a substance made of only one type of atom.
What are three examples of elements + their symbol and use
- Hydrogen (H):
- Used in fuel cells for clean energy.
- Oxygen (O):
- Vital for respiration in living organisms.
- Carbon (C):
- Key component of organic molecules.
What are some physical properties of metals
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.
What are some physical properties of non metals
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.
What are some chemical properties of metals
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.
What are some chemical properties of non metals
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).
What does the elemental symbol H stand for?
Hydrogen
What does the elemental symbol He stand for?
Helium
What does the elemental symbol Li stand for?
Lithium
What does the elemental symbol B stand for?
Boron
What are the three ways atoms can be arranged in elements?
As single atoms, molecules or lattices.
Define a molecule
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.
Describe the molecular structure of some non-metallic elements,
such as nitrogen, phosphorus, sulphur and carbon.
Nitrogen (N2) - two nitrogen atoms tightly bound together
Phosphorous (P4) - 4 phosphorous atoms bound in a tetrahedral shape
What do all metals exist as?
Crystal lattices
Define compounds
Compounds are substances made up of more than one type of atom.
Describe the difference between molecular compounds and
compound lattices
- 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)
Define molecular formula and give examples.
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).
define aqueous
Containing water
define aqueous solution
Solution containing water.
define solute
Can be dissolved
define solvent
The one dissolving stuff.
define mixture
Two or more substances physically combined.
define solution
A solution is a type of mixture where a solute dissolves completely into a solvent.
