Lava is hot for two primary reasons: Pressure and radiogenic heating make it very hot deep in the Earth (about 100 km down) where rocks melt to make magma. The rock around the magma is a good insulator so the magma doesn’t lose much heat on the way to the surface.

Since lava is a poor conductor of heat it cools slowly under neither the outside crust. Also the insulating properties of lava causes it to cool slower and slower over time.

Could I outrun the lava and make it to safety? Well, technically, yes. Most lava flows — especially those from shield volcanoes, the less explosive type found in Hawaii — are pretty sluggish. As long as the lava doesn’t find its way into a tube- or chute-shaped valley, it will probably move slower than a mile per hour.

Most lava is very hot—about 2,000 degrees Fahrenheit. At those temperatures, a human would probably burst into flames and either get extremely serious burns or die. Unlike a lake, people won’t immediately sink into lava.

In general, lava flows slowly, with typical speeds of 0.25 mph (0.40 km/h) and maximum speeds of 6 to 30 mph (9.7 to 48.3 km/h) on steep slopes. An exceptional speed of 20 to 60 mph (32 to 97 km/h) was recorded following the collapse of a lava lake at Mount Nyiragongo.

Any object that has a melting point higher than that will not melt when touched by lava. For example Diamond has a melting point of about 3550 C. It will not melt when touched by lava.

The short answer is that while lava is hot, it’s not hot enough to melt the rocks on the side of or surrounding the volcano. Most rocks have melting points higher than 700℃. So by the time it’s out of the volcano, lava is generally not quite hot enough to melt the rocks it flows over.

Dry ice is one such substance that cannot melt at normal atmospheric pressure. It undergoes sublimation, turning directly from solid to gaseous state. Wood or paper does not melt too, considering normal pressure conditions.

7,280° Fahrenheit

Burnt diamonds look almost like an ice skating rink’s thick white ice. But this damage is only surface deep! We can polish your diamonds and they will look like new. Expect a small amount of weight loss, usually about 3 – 5%, depending upon the depth of the diamond burn.

Hydrofluoric Acid

Hydrofluoric acid (HF): A weak acid, meaning it doesn’t fully dissociate into its ions in water, but it’s probably the most dangerous acid in this list because it’s the one you’re most likely to encounter.

Sulfuric acid

Fluoroantimonic acid

Hydrofluoric acid is very nasty stuff, but it isn’t a strong acid. Even when dilute it will etch glass and ceramics, but it won’t dissolve or burn flesh.

There are 7 strong acids: chloric acid, hydrobromic acid, hydrochloric acid, hydroiodic acid, nitric acid, perchloric acid, and sulfuric acid.

Some common examples of weak acids are listed below.

• Formic acid (chemical formula: HCOOH)
• Acetic acid (chemical formula: CH3COOH)
• Benzoic acid (chemical formula: C6H5COOH)
• Oxalic acid (chemical formula: C2H2O4)
• Hydrofluoric acid (chemical formula: HF)
• Nitrous acid (chemical formula: HNO2)

Any acid that dissociates 100% into ions is called a strong acid. If it does not dissociate 100%, it is a weak acid.

When going down a row in the Periodic Table (see figure below), the atoms get larger so the strength of the bonds get weaker, which means the acids get stronger. For the halogen-containing acids above, HF has the strongest bond and is the weakest acid.