Question

the list identifies various properties of four elements:
element 1 is a gas at room temperature.
element 2 is a solid which conducts electricity.
element 3 is a gas with an effective nuclear charge of +7.
element 4 is malleable and can take the form of a shiny solid sheet.
based on this list, which elements are metals?
elements 1 and 4
elements 2 and 3
elements 2 and 4
elements 1 and 3

Explanation:

Metals are typically solids (at room temperature, except mercury), conduct electricity, and are malleable (can be hammered into sheets). Element 2 conducts electricity (a property of metals). Element 4 is malleable and can form a shiny solid sheet (metals are malleable and have a metallic luster). Element 1 is a gas (most non - metals are gases at room temperature). Element 3 is a gas with an effective nuclear charge of +7 (likely a non - metal, for example, nitrogen has an effective nuclear charge in a similar range and is a gas).

Answer:

Elements 2 and 4