Explanation

Most abundant element in Earth crust is Oxygen.

Oxygen in the crust is (46.1%).

The chemical formula of oxygen (dioxygen) is O2.

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List of 10 Most Abundant Elements in the Earth's Crust

Explanation

Magnesium (Mg) electronic distribution = 2, 8, 2

The number of shells = 3 (so Period = 3)

The number of electrons in the outermost shell = 2 (so Group = 2)

Explanation

Nylon actually has excellent abrasion resistance, not poor.

It is also highly resilient, resistant to insects, fungi, and many chemicals.

Explanation

 Coal gas composition:

Typically contains around 50% hydrogen, 35% methane, and 10% carbon monoxide. 

Production method:

Coal is heated in the absence of air to produce these gases. 

Explanation

A dental filling is an example of a solution where a liquid (like mercury) is dissolved in a solid (like silver or tin).

This mixture forms a solid solution used to restore damaged teeth.