Unit 1 - AOS 1 Flashcards
How do the chemical structures of materials explain their properties and reactions?
What is an element?
pure substance only containing one type of element
What is an atom?
smallest unit of matter
What is a nucleus and what does it contain?
region in the centre of an atom that contains protons and neutrons
What is atomic number?
the number of protons in an atoms nucleus
What is a molecue?
when two or more atoms bond by sharing electrons (H*2)
What is a compound?
two or more atoms of different elements bond together (NH*3)
What is an ion?
an atom that has lost or gained electrons to become a charged particle (protons /= electrons)
What is mass number?
mass of an atom = protons + neutrons
What is an isotope?
variations of an element that has the same atomic number but different mass number due to different number of neutrons
What are periods?
rows in the periodic table
What are groups?
columns in the periodic table
What is a noble gas?
elements in group 18
What are the 3 types that the periodic table can be split into?
metals, non metals and metalloids
What do elements in the same group have in common?
similar reactivity
What do elements in the same period have in common?
same number of occupied electron shells
What are blocks?
groups elements belong to based on the location of their valence electrons
What are the 4 blocks?
s (left), p (right), d(middle), f(down)
What is an orbital?
regions with the highest probability of finding an electron
What is the max electrons an orbital can hold?
2 electrons
What does each part of subshell notation represent (1s*2)?
- subshell number
- type of subshell
- number of electrons in subshell
What is core charge?
the pull of the positive nucleus on the valence electrons
How does core charge increase?
across a period —>
How can core charge be found?
protons - inner shell electrons = core charge
What is atomic radius?
the distance from the centre of an atom to the valence electrons (radius of atom)
How does atomic radius change?
decrease across period, increase down group </ (left down)
What is periodicity?
characteristics of elements in a period (often change across period)
What is electronegativity?
the ability for an element to attract shared electrons
What traits do noble gases lack?
electronegativity and reactivity
How does electronegativity change?
increases across period and decreases down group /> (right up)
What is first ionisation energy?
the energy required to remove the first valence electron
How does first ionisation energy change?
increases across period and decreases down group /> (right up)
What is metallic character and what is it dependent on?
the degree in which an element is shiny and conductive and is dependent on how easily electrons are lost
How does metallic character change?
decreases across period and increases down group </ (left down)
What is reactivity?
how easy it is for an atom to lose/gain electrons
How does reactivity change?
metals <—
non-metals —->
