Which one of this is endothermic and which one is exothermic?

CH2+O2 - > CO2+H2O+Energy

CaCo+Energy - > CaCo+CO2

What is the molarity of the solution produced when 145 g NaCl is dissolved in sufficient water to prepare 2.75 L of solution? * a. 0.0190 b. 52.7 c. 399 d. 0.902

Which of the following correctly shows a prefix used in naming a binary molecular compound along with its corresponding number? Penta-,6; hexa-,4; deca-,8; nona-,9

Where can gold be found in a smartphone?

Which of the following describes a gas? O A. Does not have a fixed volume or a fixed shape O B. Has a fixed volume and a fixed shape O C. Has a fixed shape but not a fixed volume O D. Has a fixed volume but not a fixed shape

Which of the following items represents a chemical change? burning melting evaporation freezing The physical properties of a compound are similar to those of its elements. a. True b. False

Which samples are substance? (A) HCI (aq) (B) NaCI (aq) (C) HCI (g) (D) NaCI (s)

2. If you add water to dilute a solution, what happens to the molarity of the compound in the solution? Explain

Which of the following is NOT true of nitrogen fixation? (A) it is a process that occurs exclusively in some species of prokaryotes (B) it sometimes occurs in bacteria that are mutualistic symbionts in plant roots (C) it is the metabolic process

What two pieces of information do u need to describe force

Why are the atomic masses for most elements not whole numbers?