A) a column
example: earth alkaline metals
Answer:
Chemical reactions do not involve changes in the chemical bonds that join
atoms in compounds :
<u>False</u>
Explanation:
Chemical reaction are the reaction in which old bonds break and new bonds are formed . The formation of new bond result in formation of new compounds . This happen because new bond are result of linking different atoms by the bond.
For example : Water formation from Oxygen and Hydrogen is a chemical process :

Original(old) bonds are :
H-H bond in H2 and O-O bonds in O2
In H2 = Hydrogen is joined to Hydrogen
IN O2 = Oxygen is joined to oxygen
New Bonds =
O-H bonds in water (H2O)
Oxygen is joined to hydrogen = New Bond formation
Hence,
<u>Chemical reactions do involve changes in the chemical bonds that join
</u>
<u>atoms in compounds</u>
<u />
Explanation:
<h3>Electrical energy into heat energy..</h3>
<h2>hope it helps.</h2><h2>stay safe healthy and happy...</h2>
The empirical formula of a compound found to have 55.7% hafnium and 44.3% chlorine is HfCl4.
<h3>How to calculate empirical formula?</h3>
The empirical formula of a compound is a notation indicating the ratios of the various elements present in a compound, without regard to the actual numbers.
The empirical formula of the given compound can be calculated as follows:
- Hafnium = 55.7% = 55.7g
- Chlorine = 44.3% = 44.3g
First, we convert mass values to moles by dividing by the molar mass of each element
- Hafnium = 55.7g ÷ 178.49g/mol = 0.312mol
- Chlorine = 44.3g ÷ 35.5g/mol = 1.25mol
Next, we divide each mole value by the smallest
- Hafnium = 0.312 ÷ 0.312 = 1
- Chlorine = 1.25 ÷ 0.312 = 4
Therefore, the empirical formula of a compound found to have 55.7% hafnium and 44.3% chlorine is HfCl4.
Learn more about empirical formula at: brainly.com/question/14044066
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