True but no one know Exactly how many stars there are
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
Calculate the H positive from the pH equation: pH equals -log (H positive). This would be 10 to the -6.49. Let's call the acid HA. To calculate Ka in this equation, Ka equals H positive times A- over HA. HA is going to be the 0 0121. So, Ka=(10^-6.49)^2/0.0121. This equals 1.05*10^-13/0.0121. Ka then equals 8.65*10^-12.
% H = 100 - ( 52.14 + 34.73 )=13.13 %
<span>assume 100 g of this compound </span>
<span>mass H = 13.13 g </span>
<span>moles H = 13.13 g / 1.008 g/mol=13 </span>
<span>mass C = 52.14 g </span>
<span>moles C = 52.14 g/ / 12.011 g/mol=4 </span>
<span>mass O = 34.73 g </span>
<span>moles O = 34.73 g/ 15.999 g/mol=2 </span>
<span>the empirical formula is C4H13O2</span>
The other dude is rude wrong
The correct answer is Dmitri Mendeleev
