The four states of matter and particle motion
Grade 10 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Ari warms 250 g of water from 20 °C to 60 °C. Water takes 4.18 J per gram per °C. How many joules does it need?
Bo warms 100 g of water from 25 °C to 75 °C. Water takes 4.18 J per gram per °C. How many joules does it need?
Esme warms 150 g of water from 30 °C to 90 °C. Water takes 4.18 J per gram per °C. How many joules does it need?
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Energy added to 100 g of H₂O (computed from standard values)
energy added (kJ) temperature (°C) state 0 −20 ice 4.2 0 ice 20.9 0 ice and water 37.6 0 water 58.5 50 water 79.4 100 water 192.4 100 water and steam 305.4 100 steam Between 4.2 and 37.6 kJ the temperature stays at 0 °C. What is the added energy doing, Jun?
- Making the molecules move faster, which the thermometer is too slow to show
- Loosening the ice's fixed pattern so it melts, not raising the temperature
- Nothing yet: the heater starts working once the temperature rises
At 192.4 kJ the sample is at 100 °C. What is in the container, Luz?
- Just steam, because 100 °C is the boiling point
- Just liquid water, because the temperature has not passed 100 °C
- A mix of liquid water and steam
Gas A is at 300 K and gas B at 600 K. How do their average kinetic energies compare, Milo?
- They are equal, since both are gases and gases of any kind share one energy
- B's is four times A's, since kinetic energy depends on the square of the speed
- Twice: average kinetic energy is proportional to kelvin temperature
Noah warms air from 27 °C to 54 °C and says the average kinetic energy doubled. Is that right?
- No: 300 K to 327 K is a rise of only about 9%
- Yes: 54 is double 27, so the energy doubled as well
- No: the air expanded as it warmed, so its energy dropped
Water at 100 °C and 1 atm (real data, NIST)
state density (g/cm³) liquid 0.958 steam 0.000598 Steam takes about 1,600 times the volume of the same mass of liquid water. What does this show about the molecules, Pia?
- Each molecule grows about 1,600 times larger in steam
- There are about 1,600 times more molecules in the same mass of steam than in the water
- They are far apart in steam, so it is mostly empty space between molecules
Melting and boiling points at 1 atm (real data, CRC)
substance melting point (°C) boiling point (°C) nitrogen −210.0 −195.8 ethanol −114.1 78.4 sodium 97.8 883 iron 1538 2861 mercury −38.8 356.7 At −100 °C, what state is ethanol in, Tala?
- Liquid: −100 °C is above −114.1 °C and below 78.4 °C
- Gas, because −100 °C is far from its melting point
- Solid, because −100 °C is well below the 0 °C freezing point
Sodium is heated from 25 °C to 500 °C. What does it do, Zee?
- It melts at 97.8 °C and boils before it reaches 500 °C
- It melts at 97.8 °C and stays liquid, since 500 °C is below 883 °C
- It stays solid, because most metals need more than 500 °C to begin melting