ch. 4 Flashcards
What’s the difference between a ball and stick model and a space filling model of a compound
-ball and stick model shows the amount of atoms –space filling model shows the size of atoms in a molecule
why is it easier to separate substances in a mixture than the elements in a compound
mixtures are combined physically and can be separated physically, compounds have to be separated chemically
Chemical bond
An attractive bond that holds atoms together
ionic substances
metal and non-metals
solids at room temp
compounds made up of ions
Molecular substances
Non-metal and nonmetal
made up of molecules
can be solid liquid or gas at room temperature
How does the structure of a substance affect its properties
Very strong bonds = harder to break
weak bonds = easier to break
ionic compounds are
Held together by very strong bonds
-Therefore it requires higher temperatures to break bonds
Bonds of molecular substances are
Weaker
so it requires less heat to break bonds
Network structure
high bonds+ high melting point
Which substance melts easier sugar or salt?
sugar melts easier because it’s a molecular substance meaning the bond is weaker
why do atoms bond
To become more stable
ionic bonds are formed between oppositely charged..
ions
covalent bonds are formed by the ___ between atoms
Sharing of electrons
covalent bonds are ___conductors of electricity
poor
Nonpolar covalent bonds
Bonds in which atoms share electrons equally
an unequal sharing of electrons forms a ___ covalent bond
polar
polar covalent bonds
formed between atoms of different elements
metallic bond
Bond formed by the attraction between positively charged metal ions and electrons around them
metals conduct ____ and conduct ____
electricity and heat
