Answer:
Scandium
Explanation:
Mendeleev played an important role in the development of the modern periodic table. His periodic table was filled with gaps. He said that these gaps were elements that were yet to be discovered. He rightly predicted many elements which have now been discovered and fitted in their proper places in the periodic table.
He used the prefix ''eka'' to refer to elements whose properties were alike but were yet to be discovered at that time.
The compound named ekaboron which he predicted to have an atomic weight between 65 (zinc) and 75 (arsenic) with a valence similar to aluminum was later discovered in 1879 and properly named scandium.
Answer:
0.355 N of HF
Explanation:
The titration reaction of HF with KOH is:
HF + KOH → H₂O + KF
<em>Where 1 mole of HF reacts per mole of KOH</em>
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Moles of KOH are:
0.0296L × (0.120 equivalents / L) = 3.552x10⁻³ equivalents of KOH = equivalents of HF.
As volume of the titrated solution was 10.0mL, normality of HF solution is:
3.552x10⁻³ equivalents of HF / 0.010L =<em> 0.355 N of HF</em>
Answer:
True
Explanation:
White blood cells play a key role in the immune system and fighting cancer.
The number is 45
hope this helps
Answer:
D
Explanation:
A synthesis reaction is a reaction in which two or more reactants combine to form a given product.
If we look closely at option D, you will notice that sulphur and oxygen combined together to form sulphur dioxide. That is a typical example of chemical synthesis.
Hence;
S + O2 ----->SO2 is a synthesis reaction.
