$(a)$ Write the names of three isotopes of hydrogen.
$(b)$ State one use of an isotope of uranium.
$(c)$ Isotopes of an element have similar chemical properties. Why?

(N/A) The three isotopes of hydrogen are:
$1.$ ${ }_{1}^{1} H$ - Protium
$2.$ ${ }_{1}^{2} H$ - Deuterium
$3.$ ${ }_{1}^{3} H$ - Tritium
$(b)$ An isotope of uranium,${ }_{92}^{235} U$,is used as a fuel in nuclear reactors to generate electricity.
$(c)$ Isotopes of an element have similar chemical properties because they have the same atomic number and the same number of valence electrons,which determines their chemical behavior.