C2. Atoms, ions and compounds

What does the nucleus of an atom contain?

protons and neutrons

Electrons are arranged around the nucleus in ___

shells

How do chemists compare the masses of subatomic particles?

using relative masses

How does the mass of a proton compare to that of a neutron?

they have virtually the same mass

What is the mass of an electron in comparison to the mass of a proton?

1/1836 th the mass of a proton

Accurately does a neutron have a slightly smaller or greater mass than a proton?

greater

What is the factor by which a neutron is bigger than a proton?

1.001375

what is the charge on a proton?

positive

what is the charge on an electron?

negative

what is the charge on a neutron?

has no charge

What can neutrons be thought to do?

provide the glue that holds the nucleus together despite the electrostatic repulsion between its positively charged protons

What happens to the number of neutrons as the nucleus gets larger?

increases

What is the atomic number?

the number of protons of an element

what is an ion?

a charged atom

why is an ion charged?

the number of electrons is different to the number of protons

what is the name of a positive ion?

cation

what is the name of a negative ion?

anion

what is a cation?

atoms with fewer electrons than protons

what is an anion?

atoms with more electrons than protons

What’s the link between the number of protons of an ion and atom of an element?

they are the same

What’s the link between the number of electrons of an ion and atom of an element?

they are different

what is the definition of an isotope?

atoms of the same element with different numbers of neutrons and different masses

how does the electron number vary between different isotope of the same element?

stays the same

Do different isotopes of an element react differently? Why?

no as they have the same number of electrons

what is relative isotopic mass?

the mass of an isotope relative to 1/12 th of the mass of an atom of carbon 12

what is relative atomic mass, Ar?

the weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon 12

what does the weighted mean mass take account of?

the percentage abundance of each isotope and the relative isotopic mass of each isotope

how are the percentage abundances of the isotopes in a sample of an element found?

using a mass spectrometer

On a mass spectrometer the greater the abundance of ions ___

the larger the signal

what does the term weighted mean mass mean?

The mean mass taking into account the relative abundancies of the isotopes

what is a binary compound?

a compound that only contains two elements

What is a polyatomic ion?

an ion that contains atoms of more than one element bonded together

which type of compound doesn’t contain ions?

covalent compounds

what is the symbol of an ammonium ion?

NH₄⁺

what is the symbol of a hydroxide ion?

OH^-

what is the symbol of a nitrate ion?

NO₃^-

what is the symbol of a nitrite ion?

NO₂^-

what is the symbol of a hydrogen carbonate ion?

HCO₃^-

what is the symbol of a manganate(VII) (permanganate) ion?

MnO₄^-

what is the symbol of a carbonate ion?

CO₃^2-

what is the symbol of a sulfate ion?

SO₄^2-

what is the symbol of a sulfite ion?

SO₃^2-

what is the symbol of a dichromate (VI) ion?

Cr₂O₇^2-

what is the symbol of a phosphate ion?

PO₄^3-