How long does it take for 87.5 % of each isotope(Krypton-73, Krypton-74, Krypton-76, and Krypton-81) to decay?

Balance and in which category does it fit in? single or double displacement or synthesis or decomposition? (a) k2 o → k + o2 (b) na + i2 → nai (c) cu(no3 )2 + naoh → cu(oh)2 + nano3 (d) kclo3 → kcl + o2 (e) ca(no3 )2 + hbr → cabr2 + hno3 (f) sn(oh)2 → sno + h2 o (g) p4 + n2 o → p4 o6 + n2 (h) fe + al2 (so4 )3 → feso4 + al (i) alcl3 + na2 co3 → al2 (co3 )3 + nacl (j) c3 h6 + o2 → co2 + h2 o

Glucose (c6h12o6) is an important biological molecule. (round the answer to nearest hundredth.) what is the percent by mass of carbon in glucose?

What is the best describtion of the side of the moon that faces earth?