Answer (score: 1): 14. Select two elements that can have an oxidation state +1 in compounds. 3) Br 4) Mg 5) Be 1) Rb 2) Cd Answer (score: 1):

The oxidation state of an element in a compound is the charge that the element would have if all bonds to atoms of different elements were 100% ionic. In this question, we are asked to select two elements that can have an oxidation state of +1 in's:<br /><br />1) Rb (Rubidium): Rubidium is an alkali metal and typically has an oxidation state of +1 in compounds. This is because alkali metals have one valence electron that they can lose to form a +1 charge.<br /><br />2) Cd (Cadmium): Cadmium is a transition metal and can have multiple oxidation states, including +2 and +4. However, it does not commonly have an oxidation state of +1 in compounds.<br /><br />3) Br (Bromine): Bromine is a halogen and typically has an oxidation state of -1 in compounds. It can also have an oxidation state of +1 in compounds, but it is less common.<br /><br />4) Mg (Magnesium): Magnesium is an alkaline earth metal and typically has an oxidation state of +2 in compounds. It does not commonly have an oxidation state of +1 in compounds.<br /><br />5 (): Beryllium is an alkaline earth metal and typically has an oxidation state of +2 in compounds. It does not commonly have an oxidation state of +1 in compounds.<br /><br />Based on the analysis, the two elements that can have an oxidation state of +1 in compounds are:<br /><br />1) Rb (Rubidium)<br />3) Br (Bromine)<br /><br />Therefore, the correct answer is 1) Rb and 3) Br.