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
Answer:
Because it goes through the process of sublimation.
Explanation:
"They are harder than alkali metals" is a characteristic property of the alkaline earth metals.
<u>Option:</u> C
<u>Explanation:</u>
The strength of metallic bond is stronger in alkaline earth metals than alkali metals because of the existence of 2 electrons in its outermost or valence shell relative to alkali metal which has only 1 electron in valence shell. Thus alkaline earth metals are therefore harder than the alkali metals.
They are considered alkaline since they formulate solutions that have a pH higher than 7, rendering them alkaline or bases. Radium is produced by uranium decay, not all alkaline elements are radioactive. It's very toxic, and the handling is risky. Calcium and magnesium are essential for animals and plants.
First Magnetic Separation to remove the iron fillings.
Next Dissolution of the sand and salt in water, and Filtration to separate the salt solution from the sand.
Evaporation of the salt solution to get back the salt.
Answer:
He concluded that atoms contain small negatively charged particles that are called electrons.
