What does temperature measure at the level of particles?

The total energy stored in all the particles added together The average kinetic energy of the particles in a substance How many particles are vibrating at any one moment The speed of the slowest particle in the substance

What is heat, in scientific terms?

The total kinetic energy of all particles in an object A fluid that flows from hot objects into cold ones Energy transferred between objects because of a temperature difference The temperature of an object measured on the Celsius scale

In which direction does heat naturally flow between two objects at different temperatures?

From the cooler object to the hotter one — heat seeks the warmest place Equally in both directions at the same rate From the hotter object to the cooler one — never spontaneously the other way Heat does not flow — it stays inside whichever object originally had it

A large swimming pool is at 20 °C. A small mug of tea is at 80 °C. Which has more total thermal energy?

The mug of tea — it has a higher temperature, so it must have more total energy They have the same energy — conservation of energy means both must be equal The pool — it has vastly more particles, so its total thermal energy is enormous even though each particle has less energy on average The mug — heat energy is more concentrated at higher temperatures

A hot metal block is placed against a cold metal block and left alone. What happens?

The hot block keeps gaining heat from the surrounding air The cold block stays cold because it resists heat flow The hot block cools and the cold block warms until both reach the same temperature — thermal equilibrium The hot block instantly transfers all its energy to the cold block

What is absolute zero?

0 °C — the temperature at which water freezes The temperature of deep outer space, around −100 °C The temperature at which particles have the minimum kinetic energy allowed by physics — approximately −273 °C The temperature at which all substances become solid

Why do scientists use the Kelvin scale rather than Celsius for thermodynamic calculations?

Kelvin values are always larger than Celsius, which avoids rounding errors Celsius goes negative below freezing, which makes subtraction confusing The Kelvin scale starts at absolute zero, so temperatures are always positive and directly proportional to particle energy Kelvin is only used for temperatures above 1000 degrees, such as in stars

Water freezes at 0 °C. What is this temperature on the Kelvin scale?

0 K 100 K 273 K 373 K

A metal spoon and a wooden spoon are both in a room at 20 °C. You pick up the metal spoon and it feels cold. Why?

The metal spoon is actually at a lower temperature than the wooden spoon Metal stores cold energy internally and releases it into your hand when touched Metal conducts heat away from your hand much faster than wood, so your hand loses energy quickly — that rapid loss is what you feel as 'cold' Wood absorbs heat from your hand first, leaving none for the metal spoon

Lord Kelvin noticed that gas experiments pointed to a minimum temperature. What did those experiments show?

Gases froze solid at −273 °C, which seemed like a natural stopping point All substances exploded at exactly −273 °C, marking the lowest safe temperature As temperature fell, the volume of a gas shrank steadily — extrapolating the trend showed volume reaching zero at about −273 °C, implying a physical lower limit to temperature He chose −273 °C because it was the coldest temperature ever measured in a laboratory at the time