Explanation

Diamond is a non-metal with a high-density.

Graphite: A non-metal but has a lower density (~2.2 g/cm³).

Hydrogen: The lightest element with very low density (~0.000089 g/cm³).

Helium: Also very low density (~0.00018 g/cm³).

Diamond: A non-metal form of carbon with high density (~3.5 g/cm³).

Iron: A metal, so not a valid choice for a non-metal category.

Explanation

Explanation

Nitrogen makes up about 78% of Earth's atmosphere,

It is the most abundant gas.

It is essential for plant growth as.

It is a key component of proteins and DNA.

Nitrogen is the chemical element with the symbol N and atomic number 7.

It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772.

Explanation

• Isotopes of an element have the same atomic number (number of protons).
• It means they have the same chemical properties and are considered the same element.

Explanation