Answer:
Should be number 4, quartz.
Explanation:
Quartz is rougher than calcite, therefore it's able to scratch it.
Answer:
The plum pudding model would have to be true as well because it shows that electrons are scattered within an atom.
Explanation:
I took the test and got it right :)
Fluorine, Chlorine, Bromine, Iodine and Astatine are representing the family of elements called : halogens.
Halogens:
- all have 7 electrons in their outer shell,
- are very reactive elements,
- form - 1 ions.
Answer: C ) They have same chemical properties.
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
