There are three isotopes of X element (X): X-17 isotope: atomic mass17.2 amu, abundance:78.99%
X-18isotope: atomic mass 18.1 amu, abundance 10.00%
X-19isotope: atomic mass:19.1 amu, abundance: 11.01%
Calculate the average atomic mass of X.

Which one of the following is an oxidation-reduction reaction? naoh + hno3 --> h2o + kno3 naoh + hno3 --> h2o + kno3 so3 + h2o --> h2so4 cacl2 + na2co3 --> caco3 + 2 nacl ch4 + 2 o2 --> co2 + 2 h2o al2(so4)3 + 6 koh --> 2 al(oh)3 + 3 k2so4