When ammonium chloride is dissolved in water, the beaker gets cold. Which type of reaction does this describe O exothermic
O endothermic
O both exothermic and endothermic
O neither exothermic nor endothermic

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

Acompound contains c, h, and o atoms. when 1.130 g of the compound is burned in oxygen, 1.064 g co2 and 0.3631 g h2o are produced. what is the empirical formula of this compound?