Periodic Table Flashcards
What is a molecule
Two or more atoms bond by sharing electrons
Compound
When atoms are from different elements
Mass number
Number of protons-number of neutrons
Neutrons
Mass number-atomic number
Isotopes
Atoms of the same element can have different mass numbers. They have same atomic number but different number of Nuclei
Maximum number of electrons for each shell
Shell1:2
Shell2:8
Shell3:18
Shell4:32
Valence electrons
Electrons in the outermost shell of an atom
Core charge formula
Number protons - inner shell electrons
Atomic radius definition
Distance from Centre on atoms to valence electrons
Electronegativity trends
High for non metals
Group 18 no electronegativity
Less pull when valence electrons further from nucleus
First Ionisation energy
The energy required to remove first valence electron from atom
First Ionisation Trends
Decreases going down a group
Increases across a period
Metallic character
Easily lose electrons, conducts electricity and shiny
Non- metallic character
Non- metals, gain electrons
Metalloids
Mix of both metallic and non metallic
Metallic trend
Going across a period decreasing metallic character
What is reactivity
How easy it is for an atom to gain or lose electrons
Reactivity trends
Group 1 most reactive followed by group 2 in the metals but in the non metals it’s group 17 followed by group 16
Group 18 no reactivity
Increase as you go up a group
Atomic radii trends
Decrease from left to right across a period to group 18
Increase as you go down a group
Electro negativity trends
Group 18 no electronegativity
Increase across a period and up a group
why a neutral atom cannot have the atomic configuration of 6 protons, 13 neutrons and 13 electrons.
Neutral atoms must have the same number of protons (positively charged) and electrons (negatively charged). If a species had 6 protons and 13 electrons, it would have an overall charge of +7, which would make it a charged species (ion).
Tellurium is element 52 and iodine is element 53. Explain why iodine atoms have less mass than tellurium atoms.
Tellurium atoms have more neutrons than iodine, resulting in a higher mass number and higher mass.
what is an ion?
An atom or a molecule that has a positive or negative electrical charge. not neutral charge. (due to the loss or gain of one or more electrons.)
Which of the following determines the chemical properties of an element?
The chemical properties of an element are determined by the electron configuration of its orbiting electrons as these interact with other atoms to form chemical bonds.
How can the periodic table of the elements be used?
To predict how atoms of different elements will combine
what is an atomic emission spectrum
the pattern of lines formed when light passes through a prism to separate it into the different frequencies of light it contains.
Emission Spectrum definition
Light contains energy. If an atom has extra energy, it can get rid of it by sending out a little packet of light, called a photon. It also works the other way around: if a photon comes near an atom that could use some extra energy, the photon can be absorbed by the atom
how many electrons can occupy subshells 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f
1s=2
2s=2
2p=6
3s=2
3p=6
3d=10
4s=2
4p=6
4d=10
4f=14
Energy consumption of absorption spectra and emission
An absorption spectrum
is produced when
atoms absorb energy.
An emission spectrum
is produced
atoms release energy.
Appearance of both spectras
Absorption spectra show dark lines or
gaps
Emission spectra show colored lines.
Energy of an atom both spectrums
An atom obtains a higher energy level when an absorption spectrum is
given by that atom.
An emission spectrum is given when an excited atom obtains a lower
energy level.
