Chemistry

Which of the following describes a substance in the solid physical state? The substance compresses significantly. The substance has a variable volume. The substance has a variable shape. all of the above none of the above

Which of the following is an example of a physical change? changing color releasing heat forming an insoluble solid dissolving a substance none of the above

Which of the following processes produces a decrease in the entropy of the system? D dissolution of solid KCI in water D melting ice to form water D boiling water to form steam mixing of two gases into one container D freezing water to form ice

Only about 25% of useful energy is produced in combustion (cars) True False

Question 2 Describe the difference between molecular and ionic compounds. square

Mixture A was made by mixing different components together but it appears to have one phase. Which term best categorizes mixture A? colloid solution emulsion suspension

Which of the following are the reactants of the chemical equation 2H_(2)+O_(2)... 2H_(2)O O_(2) C_(3)H_(13) H

Hexane, C_(6)H_(14) would have which of the following fragments in its mass spectrum? Check all that apply. (m)/(z)=32 (m)/(z)=57 (m)/(z)=29 (m)/(z)=43

Which neutral atom has the following electron configuration: 1s^22s^22p^63s^23p^64s^23d^104p^65s^24d^105p^66s^2 Enter the chemical symbol for the element. View Available Hint(s)

Calculate the density in grams per liter of HF at STP. Be sure your answer has the correct number of significant figures. Note: For molar mass calculations, round to the hundredths place. square (g)/(L)