Atoms, ions and compounds chp 2 Flashcards
what is the overall charge of an atom
zero, as there are the same number of positivly charged protons and negativly charged electrons
what does the atomic number represent
the number of protons in the atom
what makes elements different from one another
different elements have different number of protons
How does the perdioic table list its elements
it is listed in order of protons or atomic number
what differes between atoms of the same element to produce isotopes
atoms and isotopes of the same elements have different numbers of neutrons but the same number of protons and electrons
what does the mass number represent
the number of protons and neutrons in the atom
the definition of ion
A charged atom, the number of electrons is different from the number of protons
what is a cation
atoms with fewer electrons than protons to have a positive overall charge
what is an anion
atoms with more electrons that protons to give the ion a negative overall charge
how is the mass of a carbon-12 atom used
1/12 of its mass is used as a standard mass to which all other masses of atoms and isotopes are compared
Definition of relative isotopic mass
the mass of an isotope relative to 1/12th the mass of an atom of carbon-12
Definition of relative atomic mass
the weighted mean mass of an atom of an element compared to 1/12th the mass of an atom of carbon-12
what does the weighted mean mass of an atom take into account
- the percentage abundance of each isotope of that element
- the relative isotopic mass of each isotope
how would you find the abundance of isotopes in a sample of an element
they can be found experimental using a mass spectrometer.
what are the basic steps to complete a mass spectroscopy
1)A sample is placed in the mass spectrometer
2)The sample is vaporised, then ionised to from positive ions
3)The ions are accelerated, heavier ions move more slowly and are more difficult to deflect than lighter ions, so the ions of each isotope are separated
4)The ions are detected on a mass spectrum as a mass-to-charge ratio (M/Z), each ion reaching the detector adds to the signal, so the greater the abundance the larger the signal
what ions do different parts of the peridoic table produce
-Atoms of metals on the left of the periodic table lose electrons to form cations.
-Atoms of non-metals on the right of the periodic table gain electrons to form anions
what are polyatomic ions, what are some examples of polyatomic ions
an ion containing atoms of more than 1 element bonded together.
