Question

What happens to lava as its temperature increases?

Answer 1

Increasing temperature in lava leads to an increase in its thermal energy, causing more vigorous molecular motion and keeping the lava in a liquid state for a longer period. Cooling of the lava involves energy transfer to its surroundings by radiation and conduction, with notable effects such as steam production when lava encounters colder matter.

Step-by-step explanation:

As the temperature of lava increases, the thermal energy content of the lava also increases. This increase in thermal energy causes the vibrational motions within the material to become more vigorous. As a result, when we consider the formation of igneous rock, lava that has a higher temperature will remain in a liquid state for a longer period before it cools and freezes into solid rock. The physical processes associated with a large body of cooling lava involve the transfer of energy through radiation and conduction. Specifically, the rate of energy transfer by radiation from the surface of lava into the surroundings can be calculated using the difference in temperature between the lava's surface, its interior, and the surrounding environment.

The scenario detailed here, with lava cooling from 1200°C in the interior to 450°C at the surface, highlights how heat dissipates from the hotter to the colder areas. The process is analogous to when lava flows into cold ocean water, transferring heat so rapidly that steam is produced. Therefore, as lava temperatures increase, the lava will continue to behave as a hotter substance, capable of transferring high amounts of energy to cooler surrounding areas until an equilibrium is reached.

Answer 2

I will assume you mean liquid lava, that is, magma that has been expelled by a volcano, and is flowing downhill, until it cools and solidifies as lava rock. Liquids typically have a generally inverse relationship between viscosity (resistance to flow) and temperature. That is, as the temperature increases, viscosity generally decreases (i.e., the lava gets “thinner” and “runnier”), as Gopismhas said. However, generally, in nature, lava doesn’t increase in temperature, but rather cools as it is expelled and flows downhill, and thus it is getting more and more viscous…until it solidifies.