Cobalt-59 and Cobalt-60 differ in that they have different mass number which means they have different number of neutrons. Isotopes are atoms of the same element with similar atomic number but different mass number. Cobalt-60, has a number of uses, which includes, being used to irradiate food sources as a method of preserving food, used in industrial radiography to detect structural flaws in metal parts among other uses.
Answer: Please see answer below
Explanation:
Mecury vapor lamp is better to use than Sodium vapor light, this is because because
---The Filaments of the lamp in sodium emit fast moving electrons, which causes valence electrons of the sodium atoms to excite to higher energy levels which when electrons after being excited, relax by emitting yellow light which concentrates on the the monochromatic bright yellow part of the visible spectrum which is about 580-590 or about (589nm) which will fall incident on the calibrations making it difficult to see
While
In Mercury vapor lamp, The emitted electrons from the filaments, after having been excited by high voltage, hit the mercury atoms but the excited electrons of mercury atoms relax and emits an ultraviolet uv invisible lights falling on the mecury vapour lamp to produce white light covering a wide range of (380-780 nm) which is visible that is why it is used for calibrations purposes in lightening applications.
Answer:- 
Explanations:- Let's say the first molecule is A and the second molecule is B and the product molecule is C.
From given information, 2 molecules of A react with 3 molecules of B to produce 5 molecules of C.
We write the reactants on left side and the product on right side and there is an arrow between them from reactants towards the products.
So, the reaction could be represented as:

Tsunamis are the largest waves in the world. The edges of the plates, where earthquakes and volcanoes often occur, usually lie near the edges of the oceans