Barium is an element that is primarily used in fireworks because of its distinct green colour while on the other hand, lead is used in electrical industries due to its unique properties. The ions of these elements can simply be identified when its insoluble salts get precipitated by any process.
A scientist needs to check several parameters before coming
to a conclusion about the amount of water pollution. The scientists needs to
check the amount of dissolved oxygen in the water, temperature of the water,
the clarity of the water, the PH level of the water and also the amount of
bacteria present in the water. There may be other criteria’s, but the mentioned
ones are enough to gauge the amount of pollution in the water. Scientists often
takes fish and aquatic plants from the water to be tested to check the amount
of pollution indirectly affecting these species.
Answer:
4- radioactive isotopes
Explanation:
I don't remember exactly but this question was on the regents
4 protons the number of proton has the same number of electron [which is the same as atomic number]
A way to explain it is that back then all the continents were together but soon after drifted apart the were in the same place sort of put they drifted apart so that's sorta what happened. Hope that helps a little