Flashcards
Chemistry 2
Cards in this deck (38)
- 1When are ions formed?When an atom loses or gains one or more electrons
- 2What happens to a positive ions?Lose electrons to from positive ions
- 3What happens to negative ions?Gain electrons to form negative ions
- 4Number or charges on a positive ionIs the same as the group number of the element
- 5Number of charges on negative ionIs (8 - group number of element)
- 6What is a noble gas structure like?Stable electronic structure
Have 8 electrons on outer shell
No tendency to lose or gain electrons
Example: neon and argon atoms - 7What is an ionic compound?It contains positive and negative ions, formed when atoms transfer electrons
- 8Features of group 1 elementsMetals
React with non metals to form ionic compounds
Produce ions with 1+ charge - 9Features of group 7 elementsNon metals
React with metal elements to form ionic compounds
Produce ions with 1- charge - 10Ionic bondsAn ionic compound is a GAINT STRUCTURE of ions. They are help in a regular arrangement called a lattice.
Are strong electrostatic forces of attraction between oppositely charged ions - 11Metal atoms....lose one or more electrons
number of charge = same as group number - 12Non-metal atoms...Gain one or more electrons
(8 - group number) - 13What is a covalent bond? Where are they formed?Form when atoms share electrons.
It is a shared pair of electrons. It forms between two non-metal atoms. - 14What is a simple molecule + example?It contains only a few atoms joined together by covalent bonds
Hydrogen - 15Properties of simple moleculesLow melting point
Low boiling point
Tend to be gases or liquids at room temperture
- 16What is intermolecular forces and where are they found?Week attractive forces between simple molecules
When melted or boiled:
Intermolecular forces are easy to overcome or break but the covalent bonds do not break
- 17What is a macromolecules and a example of what they can be?They have giant covalent structure/ Each molecule contains very many atoms joined together by covalent bonds
They can be elements (diamond) or compounds (silica) - 18What properties must a substance have to conduct electricity?+ must have electrically charged particles
particles must be free to move - 19Do substances with simple molecules conduct electricity?substances that consist of simple molecules cannot conduct electricity because the molecules do not have an overall electrical charge
- 20What are some properties of a diamond?Each atom is bonded to four others
Strong covalent bonds between atoms
Does not have delocalised electrons
High melting point
Solids at room temperature
Giant covalent lattice
- 21What is an ionic bond?Is an electrostatic force of attraction between oppositely charged ions
High melting point
High boiling point
- 22Ion propertiesIons are charged but they cannot carry an electric current
Are free to move - 23Why can metals conduct heat and electricity?Because they have delocalised electrons which are free to move through their structure which can conduct heat and electricity
- 24Why can metals be shaped easily?Because they have layers of atoms which can slide over each other.
- 25What is an alloy?Is a metal mixed with one or more other elements which is usually other metals
- 26What is shape memory alloys?Can be returned to their original shape after being stretched or bend
- 27What is a polymer?Are very large molecules made when small molecules join together
- 28What does thermosoftening polymers consist of?Individual tangled polymer chains
- 29What happens to thermosoftening polymers when heated?Soften and melted
Intermolecular forces are weakened which lets the chains slide over each other easily - 30What does LDPE stand for?Low density poly(ethene)
Flexible
Holds colder tempertures - 31What does HDPE stand for?High density poly(ethene)
Stronger
Less flexible
Holds higher tempertures - 32What size does nanoscience concern?1nm and 100nm in size
- 331nm is how many millimetres?one millionth
- 34Properties of nanosciencehigh surface area to volume ratio
- 35Why can nanoparticles be used a catalysts?Because they have a large surface area
- 36Uses of nanoparticles?Computers
Catalysts
Coatings
High selective sensors detect substances like polluting gases
Lighter ans stronger construction materials
Sunscreens
Deodorants - 37Properties of nanotubesVery strong
Conduct electricity - 38—
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- GCSE Chemistry Flashcards on Chemistry 2, created by grace.hanc on 13/06/2016.
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- grace.hanc
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