Before the bars touch, the top bar is hotter than the bottom bar. Once the bars are touching, the cooler bottom bar will gain kinetic energy until the molecules of both bars have an energy of 25, because hotter things increase the temperature of cooler things.

What happens to the molecules in the ground when the temperature of the ground increases? More heat molecules combine with the molecules in the ground. The energy of the molecules in the ground increases.

Before the chairs touch, the bottom chair is hotter than the top chair. Once the chairs are touching, the bottom chair will transfer kinetic energy to the molecules in the cooler top chair until both chairs reach the same temperature, which will be in between their starting temperatures.

Temperature is related to but not the same as thermal energy. Thermal energy and temperature both depend on the kinetic energy of the particles in a substance. Temperature does not depend upon the mass of an object. The thermal energy of a substance is a measure of the total kinetic energy of its particles.

(a) The amount of heat transferred is directly proportional to the temperature change. To double the temperature change of a mass m, you need to add twice the heat.

Minus 273.15 degrees Celsius: this is the temperature described by physicists as absolute zero – the theoretically lowest possible temperature.

At 70 degrees F (21 C), you experience “profound,” deadly hypothermia. The coldest recorded body temperature a person has ever survived is 56.7 degrees F (13.2 degrees C), according to Atlas Obscura.

The Planck temperature is the highest temperature in conventional physics because conventional physics breaks down at that temperature. Above 1032 K—that is, earlier than one Planck time—calculations show that strange things, unknown things, begin to happen to phenomena we hold near and dear, like space and time.

Nothing in the universe — or in a lab — has ever reached absolute zero as far as we know. Even space has a background temperature of 2.7 kelvins. But we do now have a precise number for it: -459.67 Fahrenheit, or -273.15 degrees Celsius, both of which equal 0 kelvin.

Summary: On the absolute temperature scale, which is used by physicists and is also called the Kelvin scale, it is not possible to go below zero – at least not in the sense of getting colder than zero kelvin. At zero kelvin (minus 273 degrees Celsius) the particles stop moving and all disorder disappears.

The electron is, as far as we know, one of the fundamental, indivisible building blocks of the universe. It was the first Standard Model particle ever discovered. Electrons are bound to an atom’s nucleus by electromagnetism.

wurtzite boron nitride

tungsten

Diamond is the hardest known mineral, Mohs’ 10. Notes: It must be noted that Mohs’ scale is arbitrary and non-linear, i.e. the steps between relative hardness values are not necessarily equal.

The strongest material in the universe may be the whimsically named “nuclear pasta.” You can find this substance in the crust of neutron stars. This amazing material is super-dense, and is 10 billion times harder to break than steel.

Although it holds the hardness record, diamond is not tough—if you smash it with a hammer, it will fracture and break.

• Diamond, pictured here in an uncut, unpolished state, is the hardest known material.
• Graphene is a one-atom-thick layer of carbon arranged in a chicken-wire pattern.

Diamonds

Talc is the softest mineral on Earth. The Mohs scale of hardness uses talc as its starting-point, with a value of 1. Talc is a silicate (like many of the Earth’s most common minerals), and in addition to silicon and oxygen, contains magnesium and water arranged into sheets in its crystal structure.

diamond

Diamond