Pure substances can or can not be chemically combined.
Pure substances can be either elements or compounds, but not mixture. Mixture are different substances mixing together without being chemically combined, such as air, which is a mixture of oxygen, carbon dioxide, water etc. Mixture can be separated by physical methods, like filtration or decantation.
Meanwhile, elements are the substances that cannot be further separated by any means. No matter physical or chemical methods. Examples of elements are oxygen, hydrogen, neon and all the other ones from the periodic table. Compounds are basically elements joining together, but they’re chemically combined which means their electrons (kind of subatomic particle) are either shared or given away. These elements can only be separated by chemical methods like electrolysis or heating.
Therefore, as long as the substance cannot be separated by physical methods, it can be considered as a pure substance. We can now conclude that pure substance can be (element) or can not be (compound) chemically combined.
There are 24 valance electrons in the compound.
<h3>What are valence electrons?</h3>
We know that the valence electrons are those that are found on the valence shell of an atom. There are four atoms that can be seen in the compound that is under consideration. The atoms are selenium, bromine (2 atoms) and oxygen.
Given that there are seven valence electrons in bromine and six valence electrons in oxygen and selenium. We have;
2(7 electrons of bromine) + 6 electrons of oxygen + 4 electrons of Se
= 24 electrons
Learn more about valence electrons:brainly.com/question/8906371
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This would be c as for the amswer
Answer:
sorry i'm not a scientist but i think it's C
Explanation:
sorry again if i get it wrong for u :(
Answer:It got to be C
Explanation: 75ml of water is