(a)
For the correct answer:
(particles are) fixed in position / in lattice OR regular / fixed arrangement / pattern
can only vibrate / no translational KE
close / closer (than in liquids or gases)
In a solid metal block, the particles are arranged in a regular, repeating pattern known as a lattice. They are held closely together by strong forces of attraction, which restricts their movement to small vibrations about their fixed positions; they possess no translational kinetic energy.
(b)(i)
For the correct answer:
(particles move) closer (as temperature decreases)
particles vibrate slower / less OR have smaller vibrations
As the temperature of the metal block decreases, the average kinetic energy of its particles reduces. This causes the particles to vibrate with less speed and amplitude, and their average separation distance decreases slightly as the block undergoes thermal contraction.
(b)(ii)
For the correct answer:
(at absolute zero particles have) least / smallest vibrations
Absolute zero ($-273^{\circ}\text{C}$ or $0\text{ K}$) is the lowest possible theoretical temperature. At this limit, particles within the metal block would possess the minimum possible kinetic energy and would exhibit only their least, or smallest, vibrations.
(c)
For the correct answer:
(P =) \(0.62 (\text{N} / \text{cm}^2)\)
(P =) 26 ÷ 42
(P =) F ÷ A
Pressure is defined as the force acting per unit area. Using the formula $P = \frac{F}{A}$, substitute the weight of the block for the force ($F = 26\text{ N}$) and the given contact area ($A = 42\text{ cm}^2$). The calculation yields $P = \frac{26}{42} = 0.619\text{ N/cm}^2$, which rounds to $0.62\text{ N/cm}^2$.
