E2 E1
Endothermic or exothermic

Asingle atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it? ok o z

Naoki's bicycle has a mass of 10 kg. if naoki sits on her bicycle and starts pedaling with a force of 168 n, causing an acceleration of 2.8 m/s2, what is naoki's mass?

Word equation for k(s)+h2o(l) yield koh(aq) + h2(g)