The number of electrons in the highest occupied energy level are the same number as the period the element is in.
Define the terms first ionization energy and electronegativity.
First ionization energy is the amount of energy needed to remove one mole of electrons from one mole of gaseous atoms.
Electronegativity is the attraction of a covalently bonded atom for a bonding pair of electrons.
Describe and explain the trends in atomic radii, ionic radii, first ionization energies, electronegativities and melting points for the alkali metals (Li → Cs) and the halogens (F → I) & Describe and explain the trends in atomic radii, ionic radii, first ionization energies and electronegativities for elements across Period 3.
Atomic Radii = the distance from the center of the nucleus to the outermost electron
As you go down a group, atomic radii increase.
As you go down a period, atomic radii decrease.
Ionic Radii = the radius ascribed to an atoms ion.
As you go down a group, ionic radii increase.
As you go down a period, ionic radii increase.
First ionization energies = the amount of energy needed to remove one mole of electrons from one mole of gaseous atoms.
As you go down a group, first ionization energy decreases.
As you go down a period, first ionization energy increases.
Electronegativities = the attraction of a covalently bonded atom for a bonding pair of electrons.
As you go down a group, electronegativity decreases.
As you go down a period, electronegativity increases.
Melting points = the temperature at which a givens solid will melt.
As you go down group 1, the melting points of the element decrease
As you go down group 7, the melting points of the element increase
The melting points are “higher” in the middle of the period table, kind of like a slope
Compare the relative electronegativity values of two or more elements based on their position in the Period Table.
Fluorine has the highest electronegativity value. Thus, the closer an element is to fluorine in the periodic table, the higher its electronegativity value is.
Discuss the similarities and differences in the chemical properties of elements in the same group.
Group 1:
As you go down Group 1, reactivity increases, as the outermost electron becomes progressively easier to remove
All the alkali metals react to exothermically with water to form hydrogen and ions of the metal hydroxide in water
Alkali metals also react readily with the halogens to form ionic halides
Group 7:
As you go down the group, reactivity decreases as the atomic radius increases and the attraction for outer electrons decreases.
The more reactive halogen displaces the ions of the less reactive halogen.
Discuss the changes in nature, from ionic to covalent and from basic to acidic, of the oxides in Period 3.
Ionic compounds are generally formed between metal and non-metal elements, so the oxides of elements Na to Al have giant ionic structures
Covalent compounds are formed between non-metals, so the oxides of P, S, and Cl have molecular covalent structures.
Silicon, which is a metalloid, has a giant covalent structure.
The oxides of Na and Mg are basic; the oxides of Al and Si are amphoteric; and the oxides of P, S, and Cl are acidic.
A basic oxide reacts with an acid to form salt and water.
A non-metallic oxide reacts with water to produce an acidic solution.
by
bohitzert (student)
