Chemical bonds Flashcards
what are trace elements
elements only in minute quantities
how do you find the mass number of an element
Number of protons+neutrons
how to find the atomic number
number of protons
how to find number of neutrons
mass number-atomic number
what are Isotopes
the same element that has a different number of neutrons
how many electrons can hold in each electron shell
first : 2, second: 8, third: 8
what is an ionic bond
one atom donates or gains one or more electrons. ions have opposite charges.
what is a Covalent bonds
two atoms share pair of electrons.
what is a molecule
two or more atoms held together by a covalent bond
how to identify Electronegativity
left of chart = smaller, right of chart = larger
what are polar bonds
atom is bonded to a more electronegative atom
hydrogen bond
exists between an electronegative molecule and a hydrogen molecule bonded to another electronegative molecule.
