In the periodic table, elements are classified into metals, nonmetals, and ___metalloids__. Metals are ductile, ____malleable, ___shiny___, are good conductors for heat and electricity. All metals are solids at room temperature and pressure except, __Mercury______. Nonmetals exist as solids, liquids or gases. A liquid non-metal at room temperature and pressure is ____Bromine_____.
The elements in the d-block in the periodic table have several characteristics in common.
(i) Give the electron configuration of N2+
1S2 2S2 2P3- 2= 1S2 2S2 2P1
(ii) Explain what is meant by a ligand and describe the type of bond formed between a ligand and a d-block element.
It is an atom or molecule with lone pair of electrons that combine with metal through coordinate covalent bonding. In transition metal compounds is sharing electron pairs between a ligand and a transition metal whereby the electron pairs come from the ligand.
(iii) Determine the oxidation number of copper and the species below
[Cu(NH2)42+ and [CuCl4]2-
X+-3x4+3x4= 2+ x+-1(4)=-2
x=+ 2 x=+2
(V) Identify the d-block element used a catalyst in the Haber process and write an equation for the reaction occurring.
Fe2+ = fe3+ e-
Determine the number of moles of NaOH present in 2g of NaOH(Atomic masses: Na= 23, 0=16, H=1)
23+16+1= 40 2 divided by 40= 0.05 mol
State the difference between Lattice energy and ionization energy.
Lattice energy- The energy required to completely separate a mole of a solid ionic compound into gaseous ions.
Ionization energy- energy necessary to remove the electron that is added in a neutral atom.
Explain why valence electrons are the only ones used in chemical bonding.
Because valence electrons are in the outermost shell of an atom and that can participate in the formation of a chemical bond. Therefore, covalent bonding occurs when pairs of electrons share their outermost electrons.