I need help with this assignment please

Which radioisotope is used in dating geological formations?

The velocity of sound wave in air at 35°c is 353m/s, calculate the velocity of sound at 46°c

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)