A blacksmith strikes a piece of metal with a hammer repeatedly. The metal slowly begins to glow as the temperature increases, and the metal becomes more malleable. Which changes on a microscopic level led to the visible changes in the properties of the metal?
a. the individual temperature of the particles increased.
b. the potential energy of the particles decreased
c. the kinetic energy of the particles decreased
d. the average speed of the particles increased
There are actually two changes on a microscopic level that led to the visible changes in the properties of the metal:
a. The individual temperature of the particles increased: As the blacksmith strikes the metal, the kinetic energy from the hammer is transferred to the metal particles. This increase in kinetic energy leads to an increase in the temperature of the metal, causing it to glow.
d. The average speed of the particles increased: The repeated striking of the metal by the hammer causes the metal particles to vibrate and move more rapidly. This increase in average speed of the particles makes the metal more malleable, as the particles can move more easily and rearrange their positions.
a or d
Both a and d are correct. The increase in individual temperature of the particles and the increase in average speed of the particles are both changes on a microscopic level that led to the visible changes in the properties of the metal.
The correct answer is:
d. the average speed of the particles increased.
When a blacksmith strikes a piece of metal with a hammer, it imparts kinetic energy to the metal at a microscopic level. This energy causes the atoms or molecules that make up the metal to vibrate with greater speed. As the metal absorbs the energy from each strike, the average speed of the metal particles increases. This increase in average speed corresponds to an increase in temperature.
As the metal particles gain kinetic energy and move faster, collisions between them become more frequent and intense. These collisions create heat, which gradually increases the temperature of the metal. As the temperature rises, the metal undergoes structural changes that lead to visible changes in its properties.
Option a (the individual temperature of the particles increased) is not correct because the temperature refers to the average kinetic energy of the particles, not the individual particles themselves.
Option b (the potential energy of the particles decreased) is not correct because the potential energy of the particles is not directly related to their kinetic energy or temperature.
Option c (the kinetic energy of the particles decreased) is not correct because the kinetic energy of the particles actually increases as they gain energy from the hammer strikes.
Therefore, the correct answer is d. the average speed of the particles increased.