It is called boiling when evaporation takes place beneath the surface of a liquid. The evaporation is a kind of vaporization only takes place at the surface of a liquid.
Answer:
A. Coal
Explanation:
= water displaced by rock
Water displaced by rock = volume of water after rock is dropped into the cylinder - volume of water before the rock was dropped into the water
Water displaced by the rock = 180 ml - 150 ml = 30 ml

Density of rock:
40 grams => 30 ml
x grams => 1 ml
Cross multiply
1*40 = 30*x
40 = 30x
40/30 = 30x/30
1.3 = x
Density of rock = 1.3 g per 1 ml
Recall: 1 ml = 1 cm³
Therefore,
Density of the rock = 1.3 g/cm³
1.3 g/cm³ falls within the range of 1.1 - 1.4 g/cm³
Therefore, the rock is identified as Coal.
Answer:
If you help I'll help you deal?
<h3>1. what is a typical characteristic of an ionic compound?</h3><h3>Answer:</h3>
Option-D : The ionic compound has a high melting point.
<h3>Explanation:</h3>
Ionic compounds are made up of positive ions called cations and negative ions called as anions. Cations are formed when an atom or group of atoms looses one or more electrons while, anion is formed when an atom or group of atoms gains electrons.
The two opposite ions formed interact through electrostatic interactions and form one of the strongest intramolecular bonding called ionic bonding. It requires very high energy to separate these ions from each other in solid form.
Examples: Melting Point of NaCl = 801 °C
Melting Point of MgCl₂ = 714 °C
Melting Point of CaCO₃ = 825 °C
_______________________________________________________
<h3>2. what is shown by the structural formula of a molecule?</h3><h3>Answer:</h3>
Option-A : The arrangement of bonded atoms.
<h3>Explanation:</h3>
Structural formula is the graphical representation of of a chemical formula in either two dimensional or three dimensional space. It helps in depicting the arrangement of atoms or group of atoms in a compound or molecule.
Examples:
Below the attached figure shows the structural formula of Glucose with Chemical formula C₆H₁₂O₆, Sulfuric Acid with Chemical formula H₂SO₄ and Water with Chemical formula H₂O respectively.