C2a Flashcards
What is the mass number?
The total number of protons and neutrons
What’s the atomic number?
The number of protons
How are compounds formed?
When atoms of 2 or more elements are chemically combined together
What’s an isotope?
Different atomic forms of the same element, which have the same number of protons but a different number of neutrons. They have the same atomic number but different mass numbers
Give an example of an isotope?
Carbon 12 and carbon 14
What happens in ionic bonding?
Atoms lose or gain electrons to form charged particles (ions) which are attracted to eachother
Shells with one or two electrons want to do what?
Get rid of the extra electron to have a full outer shell
Shells that are nearly full want to do what?
Gain an electron so they have a full outer shell, they then latch onto the ion that gave them the electron
Give an example of ionic bonding
The reaction of sodium and chlorine
What are the properties of an ionic compound’s structure?
Giant ionic lattices, closely packed lattice arrangement, strong electrostatic forces of attraction between ions
What are the general properties of an ionic compound?
High melting points and boiling points (strong attraction between the ions), when melted they’ll carry electric current, they dissolve in water (also carry electric current)
Which groups in the periodic table are most likely to form ions?
Groups 1, 2, 6 and 7
Ions have the electronic structure of a…
Noble gas
Group 1 and 2 metals lose an electron to form…
positive ions
Group 6 and 7 non metals gain electrons to form…
negative ions
The + and - charges just tell you what?
The type of ion the atom will form in a chemical reaction
The overall charge of any compund is?
Zero
What is covalent bonding?
Where atoms share electorons in their outer shells, but bond so they both have the same electron in the outer shell. They feel like they have full outer shells (think venn diagram)
Some examples of covalent bonds:
Hydrogen (H2), Chlorine (Cl2), Ammonia (NH3), Water (H2O), Oxygen (O2)
Properties of covalent substances (simple molecular):
Weak forces of attraction between molecules, low melting and boiling points, gases or liquids at room temperaature, don’t conduct electricity
What are giant covalent structures called?
Macromolecules
What are the properties of a giant covalent substance?
High melting and boiling points, don’t conduct electricity, no charged ions
Examples of giant covalent substances (structure and their uses):
Diamond- rigid giant covalent structure, hardest natural substance, used for drill tips
Graphite- layers that are free to slide over eachother, weak intermolecular forces between layers, good conductor of heat and electricity, used in pencils