An element is a pure substance
Answer:
The vertical columns are called groups.
Explanation:
Periodic table consist of vertical columns and horizontal rows.
Vertical columns are called groups while horizontal rows are called periods.
There are seven periods and 18 groups in periodic table.
The elements in same group have similar properties and can react in a similar way.
The elements in same group have same number of valance electrons that's why their reactivity is same.
Consider the example of alkaline earth metals. They are present in group two and have same number of valance electrons (two valance electrons).
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
this oxide form hydroxide when react with water,
BaO + H₂O → Ba(OH)₂
MgO + H₂O → Mg(OH)₂
CaO + H₂O → Ca(OH)₂
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
Hi. 2fouls! :)
First convert the number from kilometer to miles:


Now to find the miles per minutes,divide the miles per hours by 60 (the amount of minutes in an hour.)


The car is travelling at a speed of 0.860766667 miles/minute.
Hope this helps.
-Benjamin
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