What is 0.0006250 l in scientific notation

Iwill give extra points to who gets this right

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.

Write the balanced equation for a reaction between aqueous nitric acid (hno3) and solid lithium metal (this is a single replacement reaction)