Explanation:
Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.
When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.
Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.
As most reactive metals are placed on the left side of periodic table.
Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.
As a result, there will be increase in reactivity of metals on moving down the group.
Thus, we can conclude that given sentences are as follows.
- Elements in the same group have the same number of valence electrons.
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Elements in the same period have the same number of electron shells.
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Metallic elements become less reactive as you move left to right in a period.
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Metallic elements become more reactive as you move top to bottom in a group.
Answer:
2
Explanation:
Each orbital can hold two electrons. One spin-up and one spin-down.
1.34 moles are in 135g of Teflon.
Explanation:
Molecular formula of teflon is (C2H4)n
mass of teflon = 135 grams
atomic mass of teflon = 100.01 gram/mole
number of moles of teflon = ?
Formula used to calculate number of moles in a substance is given as:
number of moles = 
putting the values in the above equation:
number of moles = 
number of moles = 1.34 moles
Teflon is polymer which is used for making non-stick coating, in 135 grams of teflon there are 1.34 moles in it.
Answer:
Speed is measured over time.
Explanation:
