Periodic Table Flashcards
Describe where on the period table the most reactive metals are.
Left and bottom (bottom left) (lower group number and higher period number)
Describe where on the period table the most reactive non-metals are.
top and right (top right) (higher group number and lower period number)
What are the properties of metals?
Metals:
Solid @ room temp (except mercury)
Good conductors
Malleable + ductile
Shiny
What are the properties of non-metals?
Non-Metals:
Mostly gas @ room temp
Poor conductors
Brittle (when solid)
Dull
Scientifically, how does reactivity in metals work?
Note: Metals lose electrons in reactions. Reactivity increases down a group because larger atoms have valence electrons farther from the nucleus, making them easier to lose. More inner electron shells cause shielding, reducing attraction to the nucleus, further increasing reactivity.
Scientifically, how does reactivity in non-metals work?
Note: Non-metals gain electrons in reactions. Reactivity increases up a group because smaller atoms have valence electrons closer to the nucleus, making them more strongly attracted. Less shielding from inner electrons further increases this attraction, making electron gain easier.
What is the main difference between a base and an acid?
Bases contain Hydroxides (OH-) and acids contain hydrogen (H+).
What is a neutralisation reaction?
Chemical reaction in which acid and a base react with an equivalent quantity of each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.
What is an oxide?
An oxide is a compound of oxygen and another element.
What are the 4 main types of oxides?
basic oxides
amphoteric oxides
acidic oxides
neutral oxides
What is a basic oxide?
A basic oxide is an oxide that reacts with acids to form salt and water. METAL
What is an acid oxide?
Oxides of non-metal
Acidic oxides are often gases at room temperature.
React with water to produce acids.
sulphur trioxide + water ➔ sulphuric acid
SO3 + H2O ➔ HSO4
React with bases and alkalis to produce salts
carbon dioxide + sodium hydroxide ➔ sodium carbonate + water
CO2 + 2NaOH➔Na2CO3 + H2O
What is a neutral oxide?
Non-metals that form oxides that show neither basic nor acidic properties and hence do not form salts when reacted with acids or bases
Insoluble in water.
What is an amphoteric oxide?
Amphoteric oxides react as acids with bases and as bases with acids, forming salts. Examples include Al₂O₃, PbO, ZnO, and SnO. Water is a non-metal amphoteric oxide. Example: Al₂O₃ reacts with HCl as a base (forming AlCl₃) and with NaOH as an acid (forming NaAlO₂).
What is an ENC (effective nuclear charge)?
Effective Nuclear Charge (ENC) is the net attraction an outer electron feels from the nucleus. It is reduced by the shielding effect of inner electrons, which block some of the attraction from the protons (nucleus).
SIMPLY NET ATTRACTION EXPERIENCED BY AN ELECTRON
How do you calculate the ENC (effective nuclear charge?
ENC = protons – shielding (inner) electrons
How does Effective Nuclear Charge (ENC) change across and down a period?
-INCREASES L->R A PERIOD - As atomic number increases, so do protons in the nucleus, nuclear charge increases
-ENC decreases down a group, As atomic number increases, so do protons and shielding electrons, ENC estimate is constant for a group. Valence electrons are further from the nucleus, so the ENC is acting over a larger distance, weaker attraction (ie increased shielding effect)
What is atomic radius?
The atomic radius is a measure of the size of an atom, define as the distance from the nucleus to the boundary of the cloud of electrons surrounding it.
(distance from the nucleus and the outermost electron shell).
How does Atomic radius change across and down a period?
Atomic radii decreases as we go across periods.
As you move left to right across a period, the number of protons increases, pulling electrons closer due to stronger attraction. Shielding remains constant, so the Effective Nuclear Charge (ENC) increases, reducing atomic size.
It increases as we go down the groups.
As you move down a group, more electron shells are added, increasing the distance between the nucleus and outer electrons. This reduces the pull of the nucleus on valence electrons, making the atom larger.
How does ionic radius change when atoms form ions?
Cations (lose electrons): Fewer electrons reduce repulsion, and the nucleus pulls remaining electrons closer, making the ion smaller.
Anions (gain electrons): More electrons increase repulsion between them, weakening the nucleus’s hold, causing the ion to become larger.
NOTE (THEY FOLLOW THE SAME TREND NORMAL ATOMIC RADIUS)
What is valency?
Valency measures an atom’s ability to bond by gaining, losing, or sharing electrons to achieve stability. It indicates ion formation, bonding behavior, and how elements combine in compounds.
How is valency calculated?
Number of hydrogen atoms with which a single atom can bond with (1 electron per).
IF ELECTRONS <OR=4 THAN VALENCE ELECTRONS IF >4 THEN 8-VALENCE.
Simply, what is ionisation energy?
IE is the amount of energy required to remove an electron from an atom (or ion).
NOTE: AN ELEMENT MAY HAVE MULTIPLE IE’S FOR DIFF CHARGES
What is first ionisation energy?
The first ionisation energy is the amount of energy needed to completely remove an electron from a neutral atom when it is a gas. An atom that has low first ionisation energy will become an ion very easily.
