A certain element has 31 protons and 38 neutrons. What is the atomic mass 1 pol of the element? (Enter answer as a whole number with units of amu).*​

Which of the following is not a double-replacement? a.) hno3 (aq) + kho (aq) -> h2o (l) + kno3 (aq)b.) ba(oh)2 (aq) + 2hclo4 (aq) -> ba(clo4)2 (aq) + 2h2o (l)c.) naoh (aq) + hcl (aq) -> h2o (aq) + nacl (s)d.) zn (s) + 2hcl (aq) -> h2 (g) + zncl2 (s)