3. (6pts) Consider the potential energy curve shown below for two particles. Which set of two particles can give rise to the curve shown? Select all that applies.  A proton and an electron Two neutral neon (Ne) atoms Two electrons Two protons Two neutrons Explain your reasoning.

Which measurement has three significant figures?

What is the oxidation number for Group 1A metals?

What pulmonary sign/symptom constitutes the greatest urgency for medical referral?

6. (10pts) Consider the following reaction (the reaction equation is balanced):  Pb(NO3)2(aq) + 2NaCl(aq)  ⟶  PbCl2(s) + 2NaNO3(aq) 120 mL of a 0.200 M Pb(NO3)2(aq) solution is combined with 230 mL of a 0.150 M NaCl(aq) solution. Which reactant, if any, is limiting? Show all your work. When the reaction described in part (a) is complete, 3.9 g of solid PbCl2 (278.09 g/mol) is collected. What is the percent yield for this reaction? Show all your work.

What condition is most likely to result in a patient bending forward placing their arms on knees and pursed lips breathing during the onset of dyspnea?

Given the data in the table below, the enthalpy of the reaction is               2 H2S (g) + 3 O2 (g)  –> 2 SO2 (g) + 2 H2O (g) Substance ΔHf° (kJ/mol) O2 (g) 0 SO2 (g) -297 H2S (g) -20.6 H2O (l) -286 H2O (g) -242

Which type of energy is associated with stored energy?

The definition of matter is (choose all that apply) :

A particular gas exerts a pressure of [x] psi. What is the pressure in mmHg?