Sec 3 Combined Science (Chemistry) Particulate Nature of Matter topical questions

State the relative charge and approximate relative mass of each sub-atomic particle.

Chlorine has proton number 17. State the number of electrons in one neutral chlorine atom, and write the electron arrangement.

Name each change of state: (a) solid to liquid, (b) gas to liquid, (c) solid to gas directly, and state for each whether energy is taken in or given out.

An atom is written as N with nucleon number 14 and proton number 7. State the numbers of protons, neutrons and electrons in the atom.

Explain, using the kinetic particle theory, why a pure substance's temperature stays constant while it melts, even though it is being heated steadily.

A pure molten substance is cooled and its temperature recorded every minute. The readings fall steadily to 55 °C, hold at 55 °C for eight minutes, then fall again. Name the change taking place during the flat section, and explain, using the kinetic particle theory, why the temperature stays constant even though the substance continues to lose energy.

Calcium has proton number 20 and nucleon number 40. State its electron arrangement, and deduce the charge and electron count of the ion calcium forms.

Bromine exists as two isotopes with nucleon numbers 79 and 81, both with proton number 35. For one atom of each isotope, state the numbers of protons, neutrons and electrons.

A heating curve for a pure substance shows: a sloping rise to 60 °C, a flat section at 60 °C, a sloping rise to 120 °C, another flat section, then a sloping rise. Identify each section and explain the particle behaviour in the second flat section.

Atom P has proton number 11 and nucleon number 23. Ion Q is written as O with charge 2−, proton number 8 and nucleon number 18. (a) State the electron arrangement of atom P. (b) State the numbers of protons, neutrons and electrons in ion Q, and explain how the charge arises.

Sulfur has proton number 16 and nucleon number 32. Zinc has proton number 30 and nucleon number 65. (a) Write the nuclide notation for both atoms. (b) A sulfide ion carries a charge of 2− and a zinc ion a charge of 2+. State the electron counts in both ions.

A student warms a frozen sample and records its temperature every minute. The readings rise steadily to −5 °C, hold at −5 °C for six minutes, then rise steadily again to 85 °C, where they hold again. Explain what each constant-temperature section shows about the sample.