Answer:
The number of periods shows you the number of _______
<u>Electron Shell</u>
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Explanation:
<u><em>Modern periodic table is divided into Groups and Periods.</em></u>
A period is the horizontal row of the periodic table. There are <u>seven periods </u>in the periodic table.
It describes the following :
- The period in which a particular element found will show its <u>electron shell</u>
- The first period has Hydrogen and Helium = 1 - shell
- The second Period has Lithium to neon = 2- shells
A group is the vertical column of the periodic table . There are <u>18 groups</u> in total.
It describes the following :
The group number of the element is same as the<u> number of electrons in the outermost shell.</u>
The element having group 1 has = 1 electron in outer shell (example Na, K)
The element having group 2 has = 2 electron in outer shell (example Ca, Mg)
The element having group 0 has = full outer shell (example Ne Xe). these are also known as noble gases
BRASS :It is easy to form into various shapes, a good conductor of heat, and generally resistant to corrosion from salt water. 1 pipes and 2 tubes, 3 screws, 4 cartridge casings for firearms.
BRONZE :for bearings because of its friction properties, and as 1 musical instruments ,2 and medals
Sulphur :1 making car batteries, 2 fertilizer
IODINE :1 Iodine regulates skin moisture levels and aids in the healing of cuts and scars through cellular regeneration. 2 Iodine also regulates the hormones responsible for acne breakouts.3 Treating thyroid cancer.
2H20+1O2——> 2H2O should be the answer
First we have to establish the chemical reaction. As a result of adding N<span>a2CO3 and AgNO3 products formed are NaNO3 and Ag2CO3. NaNO3 is a soluble substance when dissolved in water.
As a general rule, most Ag, Pb and Hg(I) compounds are considered insoluble. Ag2CO3 is insoluble in water hence the reaction given forms a precipitate. </span>
