Answer:
When an atom loses electron(s) it will lose some of its negative charge and so becomes positively charged. A positive ion is formed where an atom has more protons than electrons. In the opposite case when an atom gains electron(s) it becomes negatively charged (more electrons than protons).
Explanation:
Answer: 69.72 kg of cryolite will be produced.
Explanation:
The balanced chemical equation is:

To calculate the moles, we use the equation:

moles of
= 
moles of
= 
moles of
= 
As 1 mole of
reacts with 6 moles of 
166 moles of
reacts with =
moles of 
As 1 mole of
reacts with 12 moles of 
166 moles of
reacts with =
moles of 
Thus
is the limiting reagent.
As 1 mole of
produces = 2 moles of cryolite
166 moles of
reacts with =
moles of cryolite
Mass of cryolite
= 
Thus 69.72 kg of cryolite will be produced.
Selenium (Se) the most common isotope of this element. The nucleus consists of 34 protons (red) and 46 neutrons (blue).
The knowledge of periodic table would be important in these three different careers such as medicine, pharmacology and engineering.
<h3>What is the importance of periodic table in following careers?</h3>
Periodic table is organised the whole elements vertically in groups and horizontally in periods with increasing atomic number.
The knowledge of arrangement of these elements serves alot of purposes in the following three different careers:
- Medicine: The element, iron is an important metal in the periodic table used in treatment of low blood levels.
- Pharmacology: The transition metals are useful in the field of pharmacology for the production of drugs. Example of such elements are chromium, manganese, cobalt, nickel, copper, and molybdenum.
- Engineering: The information of elements in the periodic table helps engineers in designing of materials used for constructions.
Therefore, the knowledge of periodic table is very important in these three different careers such as medicine, pharmacology and engineering.
Learn more about period table here:
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