Balance the following reaction. a coefficient of "1" is understood. choose option "blank" for the correct answer if the coefficient is "1." al + hcl → alcl3 + h2

When balancing an equation, you need to know how many of each atom is on each side.

Left hand side:

1 Al , 1H , 1 Cl

Right hand side:

1 Al , 3 Cl, 2 H

You need to change the numbers on each side until the same amount is on both sides:

Al + HCl → AlC₃ + H₂

Al + 3HCl → AlC₃ + H₂

Al + 3HCl → AlC₃ + 3H₂

Al + 3HCl → AlC₃ + 3H₂

Al + 6HCl → AlC₃ + 3H₂

Al + 6HCl → 2AlC₃ + 3H₂

2Al + 6HCl → 2AlC₃ + 3H₂

Which is now balanced!

The balanced equation again is:

a) the particles of the chair are strongly held together.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.