In addition to the six elements most prevalent in living things there are other elements that are required for human life. which element is necessary for humans to maintain a strong skeletal system?
a. xenon
b. calcium
c. rhodium
d. chlorine

Harvey mixes two liquids. which observation of the new mixture most likely indicates a precipitate is forming?

Stoichiometry- i need with 14 and 15! an explanation would be appreciated!

Find the enthalpy of neutralization of hcl and naoh. 87 cm3 of 1.6 mol dm-3 hydrochloric acid was neutralized by 87 cm3 of 1.6 mol dm-3 naoh. the temperature rose from 298 k to 317.4 k. the specific heat capacity is the same as water, 4.18 j/k g. a. -101.37 kj b. 7055 kj c. 10,1365 kj