Leaves turn colors in the fall. At least two of the above a-d exhibit only a physical change. Water condenses on a mirror. A damp towel dries. Peanuts are crushed. At least two of the above a-d exhibit a chemical change. Gold is a yellow metal. Gold is an inert nonreactive metal. Gold is a soft metal. Gold is a very dense metal.
Gold is a good conductor of heat and electricity. A compound can consist of one kind of element. A homogeneous mixture. A heterogeneous compound. A solid element. A mixture of solids. A solution of gases. Separating a homogeneous mixture into pure substances. Separating a heterogeneous mixture into pure substances.
Distilling a saltwater mixture. Breaking a compound into its constituent elements. At least two of the above a-d require chemical methods. Dry ice sublimes when left on the demo table in lecture. The light on a candle burns until a bell jar is placed over it for a period of time.
When a few drops of red food coloring are added to a beaker of hot water, the water immediately turns red. Liquid nitrogen dumped onto the floor vaporizes at room temperature. None of the above processes are chemical changes. Two or more atoms bonded together always form a compound. An element consists of only single atoms of that element. A solid substance is not considered matter. Carbon dioxide can exist only in the gaseous state.
The normal boiling point of water is o C, which is a physical property of the substance water. Gold is a relatively soft metal, which is a chemical property of the substance gold. Metal rusting is an example of a chemical change. Juice freezing into a popsicle is an example of a physical change. Dry ice subliming turning from a solid straight into a gas is an example of a chemical change.
Check all that apply. In naming ionic compounds, the cation is always named first and the anion second. HCN c. Various charges are possible. AlO 3 b. KBr c. KNO 3 d. TiO 4 c. TiO 2 e. Ion X contains 20 electrons. What is the identity of X? SeO 3 b. CaS 2 c. What is the correct formula for sodium carbonate? What should its name be? ANS: This answer is incorrect. KCl b. B The protons and neutrons in the nucleus are very tightly packed.
C The number of protons and the number of neutrons are always the same in the neutral atom. D The electrons occupy a very large volume compared to the nucleus. Which of the experiments listed below did not provide the information stated about the nature of the atom? B The Rutherford experiment determined the charge on the nucleus. C The cathode-ray tube proved that electrons have a negative charge. Which of the following atomic symbols is incorrect? The element rhenium Re exists as two stable isotopes and 18 unstable isotopes.
Rhenium has in its nucleus A 75 protons, neutrons. B 75 protons, 75 neutrons. C 75 protons, neutrons. D protons, 75 neutrons. E not enough information is given. Which of the following statements is are true? O and F have the same number of neutrons. C and N are isotopes of each other because their mass numbers are the same. Which among the following represent a set of isotopes? Atomic nuclei containing I.
How many protons, neutrons, and electrons does the atom 31P have? An ion is formed I. A Only I is true. B Only II is true. C Only III is true. D All of the statements are true. E Two of the statements are true. Which is the symbol for the isotope of nitrogen that has 7 protons and 8 neutrons? Which of the following represents a pair of isotopes?
The number of protons is the same for all neutral atoms of an element. The number of electrons is the same for all neutral atoms of an element. The number of neutrons is the same for all neutral atoms of an element.
Only I and II are true. Only I and III are true. If the mass number of the ion is 24 and it has 10 electrons, what is the element and how many neutrons does it have? Which element does not belong to the family or classification indicated? Which are alkaline earth halides? Select the group of symbols that would correctly complete the following statements, respectively.
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