Answer:
In 1897, the British physicist J. J. Thomson (1856–1940) proved that atoms were not the most basic form of matter. He demonstrated that cathode rays could be deflected, or bent, by magnetic or electric fields, which indicated that cathode rays consist of charged particles (Figure 2.2.2 ). More important, by measuring the extent of the deflection of the cathode rays in magnetic or electric fields of various strengths, Thomson was able to calculate the mass-to-charge ratio of the particles. These particles were emitted by the negatively charged cathode and repelled by the negative terminal of an electric field. Because like charges repel each other and opposite charges attract, Thomson concluded that the particles had a net negative charge; these particles are now called electrons. Most relevant to the field of chemistry, Thomson found that the mass-to-charge ratio of cathode rays is independent of the nature of the metal electrodes or the gas, which suggested that electrons were fundamental components of all atoms.
Explanation:
The chemical activity series is the arrangement of the elements descendingly according to their chemical activity for reactions like simple substitution reactions and redox reactions. Elements above hydrogen can replace hydrogen from water and acids as they are more active than hydrogen. Since cesium is more active than hydrogen, it replaces it in hydrochloric acid.
2 cesium atoms loses 2 electrons first;
2Cs --> 2Cs+ + 2e-
2 hydrogen atoms recieve the two electrons;
2H+ + 2e- --> H2
The net ionic equation is;
2Cs + 2HCl --> CsCl + H2
KE = (1/2)mv^2
m = 10.0 kg
v = 5.00 m/a
KE = (1/2)(10.0)(5.00)^2 = (1/2)(10.0)(25.0) = 125 J
C. 125 J