Which of the following statements, if any, are correct for the properties of Group I elements?
A. 1, 2 and 3
B. 1 and 2 only
C. 1 and 3 only
D. none of them
E. 2 and 3 only
Group 1 metals are called alkali metals.
Characteristics of alkali metals:
(1) They form hydrides where the hydrogen has an oxidation state of –1.
True. Alkali metals are in a +1 oxidative state, and when combined with hydrogen, they will form H-X compounds, where X is the Alkali in a +1 state, and H is hydrogen in a -1 state.
(2) They can reduce iodine to iodide.
True. As previously stated, they form ionic compounds with non-metals. Recall that oxidation is loss of electrons and reduction is gain of electrons (OIL RIG). In this case, we are forming compounds with the formula X-I, where X is the alkali and I is iodine. Akali metals what to donate electrons to achieve a stable octet, and iodine wants to accept one to achieve an octet. This results in iodine accepting the electron from the alkali, resulting in a reduction of iodine (reduction is gain of electrons).
(3) Their outer electrons are delocalised when in the liquid state.
True. Characteristic of metals, when in a liquid state, their outer electrons are delocalized. This explains their ability to be such strong conductors of heat and electricity.