When an element ‘X’ reacts with dilute hydrochloric acid brisk effervescence of a gas is produced, which burns with the ‘pop’ sound. a. Element ‘X’ is a metal or a nonmetal?
b. Name the gas produced in the above reaction.

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

Theoretical temperature at which molecules stop moving and no more heat can be removed from the object. kelvin: absolute zero degrees. none of the above.

Do you have any options for this question?

Tell me the answer choices and i would be able to answer. : )