Thermionic emission questions | form four Physics

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#	Question
1	A radioactive material is denoted by the symbol $_{88}^{226} extrm{X}$ . Write down the composition of the nucleus during the end of the following stages of disintegration. (i) the emission of an alpha-particle. (ii) the further emission of a beta-particle. (iii) the further emission of a gamma radiation. Short answers
2	The following represents part of the decay chain for thorium $_{90}^{232} extrm{Th} ightarrow _{88}^{228} extrm{Ra} ightarrow _{89}^{228} extrm{Ac} ightarrow _{90}^{228} extrm{Th} ightarrow _{88}^{224} extrm{Ra}$ What particles are emitted at each part of the chain? Short answers
3	A radioactive nucleus is denoted by the symbol $_{88}^{226} extrm{X}$ . Write down the composition of the nucleus at the end of the following stages of disintegration: (i) emission of an alpha ( $alpha$ ) particle (ii) further emission of a beta ( $eta$ ) particle (iii) further emission of a gamma radiation. Short answers
4	Part of a certain nuclear decay series is represented by the following unbalanced equations, in each stage only ONE type of a particle is emitted. (i) $_{90}^{232} extrm{Th} ightarrow _{88}^{228} extrm{Ra}$ (ii) $_{88}^{228} extrm{Ra} ightarrow _{89}^{228} extrm{Ac}$ (iii) $_{89}^{228} extrm{Ac} ightarrow _{90}^{228} extrm{Th}$ (iv) $_{90}^{228} extrm{Th} ightarrow _{88}^{224} extrm{Ra}$ (a) Identify the type of particle emitted in each of the above stages. (b) Write two pairs of isotopes from the above series. Short answers
5	Uranium $_{92}^{238} extrm{U}$ decays to Polonium $_{84}^{222} extrm{P}$ by α emission (at each stage) via $_{x}^{234} extrm{Th}$ , $_{y}^{230} extrm{Ra}$ and $_{z}^{226} extrm{Rn}$ . Following this process, $_{84}^{222} extrm{P}$ decays to $_{86}^{q} extrm{Rn}$ by β emission only. Write balanced equations of the stage by stage decay process from $_{92}^{238} extrm{U}$ to $_{86}^{q} extrm{Rn}$ and hence determine the values of x, y, z and q. Then Name the isotopes and isobars obtained in the decay process shown above. Short answers
6	What particle are emitted in thermionic emission? Explain why they are emitted. Short answers
7	The discharge of electrons from heated metal is known as _______ Fill in blanks
8	(i) Define thermionic emission. (ii) What is the function of metal rectifiers in battery chargers? Short answers
9	Figure 5 shows a stationary wave, W obtained on the screen when an a.c voltage, V is connected to the Y plate of an Oscilloscope. (i) What does part XY and the height, ‘b’ represents? (ii) Briefly explain how the value of ‘b’ can be achieved. Short answers
10	(i) Give four applications of X-rays in daily life activities. (ii) Explain how X-rays are produced. Short answers