Question

mixed challenge

1. compare sodium (na), calcium (ca), and chlorine (cl). which are metals and which are nonmetals? which one is most reactive overall? why?
2. gold (au) is a metal and neon (ne) is a nonmetal. why are both of these considered very unreactive, even though they are in different groups?

Explanation:

Step1: Identify metals and non - metals

Sodium (Na) and Calcium (Ca) are metals as they are on the left - hand side of the periodic table and have properties like high electrical conductivity, malleability etc. Chlorine (Cl) is a non - metal, located on the right - hand side of the periodic table, and is a poor conductor of electricity.

Step2: Determine reactivity based on periodic trends

Sodium (Na) is more reactive than Calcium (Ca) and Chlorine (Cl). Sodium is in Group 1 of the periodic table (alkali metals). Elements in Group 1 have one valence electron, which they lose easily to form a + 1 ion. Calcium is in Group 2 (alkaline earth metals) and has two valence electrons to lose. Chlorine is in Group 17 (halogens) and gains one electron to form a - 1 ion. The reactivity of metals increases as you go down a group and from right to left across a period. Sodium is more to the left in the periodic table compared to Calcium among these elements.

Step3: Explain metal and non - metal nature of gold and neon

Gold (Au) is a metal because it has typical metallic properties such as luster, high electrical and thermal conductivity, and malleability. Neon (Ne) is a non - metal. It is a noble gas in Group 18 of the periodic table. Noble gases have a full outer electron shell, making them very stable and unreactive.

Answer:

1. Sodium (Na) is the most reactive among Sodium (Na), Calcium (Ca), and Chlorine (Cl). Sodium is an alkali metal with one valence electron, which it loses easily to achieve a stable electron configuration.
2. Gold (Au) is a metal due to its metallic properties like luster, conductivity, and malleability. Neon (Ne) is a non - metal as it is a noble gas with a full outer electron shell, making it very unreactive.