What Does "X" Represent in the Following Symbol? X

Q29: Calculate the mass (in kg)of 4.87 ×

Q39: Two or more substances in variable proportions,where

Q65: The atomic number for iron is _.<br>A)

Q99: Calculate the atomic mass of element "X",if

Q123: All statements about scientific theories are true

Q129: Identify the element that has an atomic

Q130: How are gases different from solids and

Q131: Choose the pure substance from the list

Q132: Gallium has an atomic mass of 69.723

Q133: Identify the characteristics of a liquid.<br>A) definite