revision points Flashcards
what is the purpose of manganese [1v] oxide
it is a catalyst that speeds up the rate of decomposition by reducing the time taken for a given volume of oxygen to be produced
write the equation for the reaction between potassium chloride and oxygen
potassium chloride +oxygen- potassium chlorate
state reasons why hydrogen is not commonly used as fuel
[ 1] it is not readily available. [2] a mixture of hydrogen and air explodes when ignited
define atomic radius
the distance between the center of the nucleus of the atom and the outermost energy level occupied by electron/s
define ionization energy
the minimum energy required to remove an electron from the outermost energy level of an atom in the gaseous state
why does the reactivity of halogens decrease down the group?
it is because of the ease of the electron gain decrease down the group as the atomic radii increase
name the alkaline earth metals
beryllium, magnesium, calcium, strontium barium and radium
name the alkali metals
lithium, sodium, potassium, rubidium, francium and caesium
name the halogens
fluorine, chlorine, bromine, iodine and astatine
name the noble gases
helium, neon, argon, krypton, xenon and radon
state why the reactivity of alkali and alkaline earth metals increases down the group
it is due to the increasing ease of electron loss
what is the name of the electron/s in the outermost energy level and state the reason for the name
they are called valence electrons because they can be used to predict valency
why is the net charge of an atom zero
because of the equal number of protons and electrons in an atom
define a chemical formula
a representation of a chemical substance using chemical symbols which show the constituent elements and the proportions in which they are combined
define the electron arrangement or configuration
it is the distribution of electrons in energy levels of an atom
