Areaction is endothermic and has an increase in enthalpy.
to lengthen a pattern piece for sewing a garment, cut the paper pattern where indicated. it will normally state "lengthen or shorten here". open the cut to the desired amount you need to add to your pattern. place a piece of tissue paper underneath and tape in place. keep the grain line correct and even. make sure you do this to all your pattern pieces used for the garment.
yeah, a lot faster than sound.
ammonia, nh₃, is a compound of nitrogen and hydrogen.
thus, it can be broken down by chemical means into the elements nitrogen and hydrogen.
the other options are wrong, because al, sb, and pb are elements. they cannot be broken down chemically into simpler substances.
ur answer would be b hope i let me know if it is right