chapter4-basic food chemistry Flashcards
What part does protons and neutrons are same as each other?
mass
how much weight is e-?
1836 e- =one proton
how e- prefer to move?
in pairs
how many elements naturally and scientists create?
90
27
what determine which element an atom is?
number of protons
who develop the periodic table?
Russian chemist- Dmitry Mendeleyev
what is AMU? what is one AMU?
atomic mass unit- mass of a proton or neutron
not all atoms of an element have the same number of neutrons. T/F
true
what are columns called?
groups 18
what are rows called?
periods 7
how does metal usually look like? except for?
solid in rtp.
Mercury-liquid in rtp.
what are metals good at?
conduct heat and electricity.
how does half of non metals look like?
gas in rtp. brittle易碎 when solid.
what does chemical formula represent?
one molecule or unit of a compound.
what is structural formula?
show the arrangement of the atoms in the molecule.
what is chemical bond?
force hold 2 atoms together
what are shells refers to?
energy level or their principle quantum number.
how is stable element likely to form chemical bond?
least likely
what is ionic bond?
e- are transfer from one atom to another, cause both atoms have a charge.
what is ionic bond result of?
attraction between a + and - charge. e.g. NaCl
what causes a crystalline?
the regular arrangement of atoms–the result of interaction between - and
+ ions.
what happen after Na ions push away Na and towards to Cl?
cause sodium and chlorine atoms form an alternating pattern or structure.
why ionic bonds tend to disslove in water?
one end of water molecule slightly +, the other side is slightly -
where is ionic bond form?
between metal and non metal.
