Atomic structure Flashcards
what is the relative charge of protons, electrons and neutrons?
1+, 1-, 0
what is the relative mass of protons, electrons and neutrons?
1, 1/1840, 1
what is a nucleon number?
the total number of protons and neutrons
what is a characteristic of an atom?
they have the same number of protons and electrons, and hence are electrically neutral
what are group 18 elements known as?
noble gases
why are noble gases unreactive?
they have completely filled valence shells hence they do not gain, lose or share electrons to form molecules or compounds and exist as individual atoms
what do metallic atoms form when they lose electrons?
positive ions (cations)
what do non-metallic atoms form when they gain electrons?
negative ions (anions)
what is the definition of isotopes?
Isotopes are atoms of the same element with the same number of protons but different number of neutrons
what is the arrangement of electrons in an atom?
2 electrons in the first shell, 8 electrons from the second shell onwards
why do some ionic compounds end with -ide while others end with -ate
ionic compounds that end with -ide are non-metallic ions while those that end with -ate are metallic ions