A1 Flashcards
what does the nucleus contain?
what is isotopes?
-neutron and proton
-Proton mass:1 charge:+1 location:nucleus
-Neutron mass: 1 charge: 0
location:nucleus
-Electron: mass:0 charge:-1 location: shells
-Isotopes have the same number of protons but different number of neutrons.To work out neutron mass number-atomic number
what does it mean when a group has full outer shell ? (group 0)
-They have outer shells meaning they don’t react easily or most don’t react at all.It also means they have stable electronic configuration
what is ionic bonding?
-Ionic bonding occurs when an atom of an element looses one or more electrons donates to an atom of a different element
-The atom that loses the electron they become
positively charged and the atom that gains the electron becomes negatively charged because of imbalances of the protons and electrons
-Na and chloride at the end the sodium chloride and the chlorine have full outer shells becoming stable and attracted
what is electrostatic attraction?
what is a giant lattice?
-Electrostatic attraction is the forced experienced by oppositely charged particles it holds the particles strongly together.Strong electrostaic attractions give ionic compounds high melting points
-Giant lattice is a regular arrangement of positive ions and negative ions (opposite charged ions in sodium chloride form this)
what does the strength of the electrostatic force depend on?
2 things
-Ionic charge the higher the ionic charge the stronger the electrostatic force
-Ionic radii-the bigger the ionic radii the bigger the electrostatic force
summarise
-the more electrons a positive ion has the more shells it has meaning the radius will be bigger than ion with fewer shells
-ef is stronger when the ionic charge is higher when the force becomes weaker the ionic radii are bigger this is because when ionic radius is bigger ionic charge is spread over a larger surface area
what is covalent bonding?
what is dative covalent bond?
-Covalent bonding occurs between the atoms of 2 non-metals its formed when an electron share between the atoms
-dative covalent bond comes from sharing electrons from one atom.Its in place the coordinates and the x comes first in between the sharing thing
what is formed when 3 pairs of electrons are shared?
what is the relationships between the bond strengths and lengths?
-Triple covalent bond is formed eg nitrogen when you can’t share the number equally like its 7.I HAS TO 2 LAYERS EVERYTHING ELSE IS 1 LAYER
-Single bond have a greater langth than double nonds and double bonds have a greater length than the triple bond
-The shorter the length of the bond the stronger the bond is therefore triple bond is stronger than double and single
what is a lone pair?
explain the organic compound for methane?
-Lone pair is a pair of electrons not involved in covalent bonding
-Methane has a formula of ch4 each carbon atoms bonds covalently with the 4 hydrogen atoms the carbon gains the stable electron structure of neon and hydrogen gains stable electron structure of helium.4 bonds means that methane is not a flat molecule it has a tetrhedral structure this is because the bonds are as seperated from each other as possible becuase the negative electron pairs repel each other
-Organic compounds with 3 or more carbon in a chain cannot be linear because of the tetrahedral structure around each central carbon
what is metallic bonding?
what is delocalised electrons?
what is strong attraction between?
-metals are giant structures of atoms held together by metallic bonds
-metal structure is a regular lattice
-metallic bonding is caused because the electrons in the highest energy level of a metal atoms has the ability to become delocalised so they are free too move through the metal in a sea of electrons
-This gives the metal nuclei a positive charge which is attracted to the negative charge on the delocalised electron
-There is a very strong attraction between positive metal nuceli and the negative delocalised electrons and that forces in metallic bonding isn’t as strong as the ones in ionic or covalent
what is electronegativity?
what do similar electronegativites form more often?
what is polar molecule and non-polar molecule?
what is the difference in the electronegativity between the atom?
-Electronegativity of 2 atoms will determine what type of bond will form beween them
-Atoms that have similar electronegativities form covalent bonds
-non-polar molecule where electrons are distributed evenly throughout the molecule eg hydrogen sharing is electron and its shared
-polar molecule is a molecule with partial postive charge in one part of the molecule and similar negative charge in another part due to an uneven electron distribution
-difference in the electronegativity between the atom increases the bond will become more polar
-Popular elements the electrongetivityes decrease down a group and increase across a period
what is intermolecular forces?
-attraction or repulsion between neighbouring molecules
3 types:
-london dispersion forces
-hydrogen bonding
-dipole dipole
