Identify the compound. which of these is a compound?

Image 3 is a compound.

Explanation: A compound is something that consists of two or more  different elements bonded chemically.

A molecule is formed when two or more elements combine chemically.

An element is described as something which cannot be broken down by any chemical means.

We are given 4 images.

Image 1 is an element as it is showing the shell structure of Oxygen (O) element.

Image 2 is an element as only 1 element is known that is Magnesium (Mg).

Image 3 is a compound as in the structure 2 elements are shown which is bonded together. Elements present in this are Carbon (C) and Oxygen (O).

Image 4 is a molecule as in the structure 2 H-atoms combine chemically, but it cannot be considered as compound as the two elements are not different.

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3