Concept explainers
Videos
(a)
Interpretation:
The given statement has to be identified as observation, hypothesis, theory, or scientific law.
The given statement is,
The battery in my watch must be dead since it is no longer keeping time.
Concept introduction:
Hypothesis:
A hypothesis is a reasonable guess based on the limited data which acts as a foundation for the further investigation. A hypothesis is not tested and proven scientifically and the results are uncertain and it relies on the possibility.
Theory:
A theory is a well correct explanation of a natural phenomenon that is validated through observation and experimentation and it is based on wide range of data. A theory is tested and proven scientifically, the results are certain, and it relies on evidence.
Scientific law:
A scientific law is the description of an observed fact. It does not explain why the observable fact exists or what causes it.
Example:
A scientific law predicts the results of unborn child’s possible hair colors or how far a baseball travels when launched at a certain angle.
Observation:
An observation is the act of noticing something or judgment from something seen or experienced.
(b)
Interpretation:
The given statement has to be identified as observation, hypothesis, theory, or scientific law.
The given statement is,
My computer must have virus since it is not working properly.
Concept introduction:
Refer to part (a).
(c)
Interpretation:
The given statement has to be identified as observation, hypothesis, theory, or scientific law.
The given statement is,
The air feels cool.
Concept introduction:
Refer to part (a).
(d)
Interpretation:
The given statement has to be identified as observation, hypothesis, theory, or scientific law.
The given statement is,
The candle burns more brightly in pure oxygen that in air because supports combustion.
Concept introduction:
Refer to part (a).
(e)
Interpretation:
The given statement has to be identified as observation, hypothesis, theory, or scientific law.
The given statement is,
My sister wears red quite often.
Concept introduction:
Refer to part (a).
(f)
Interpretation:
The given statement has to be identified as observation, hypothesis, theory, or scientific law.
The given statement is,
A pure substance has a definite, fixed composition.
Concept introduction:
Refer to part (a).
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Chapter 1 Solutions
EBK FOUNDATIONS OF COLLEGE CHEMISTRY
- An empty Erlenmeyer flask weighs 235.6 g. When filled with water (d = 1.00 g/cm3), the flask and its contents weigh 571.3 g. (a) What is the volume of water in the flask? Enter your answer in scientific notation. (b) How much does the flask weigh when filled with the same volume of chloroform (d = 1.48 g/cm3)?arrow_forwardThe following statements pertain to the development of the theory of combustion by the French chemist Lavoisier in the eighteenth century. Match the statement with the appro- priate step (observation, hypothesis, experiment designed to test hypothesis) in the scientific method. (a) A metal is burned in a closed container, and the change in mass of the solid and volume of the gas is measured.(b) Oxygen gas combines with a substance during its combustion.(c) Combustion of a metal in a closed container ceases after a length of time.arrow_forwardWhich of the following statements is a scientific theory? (a) The energy in an atomic nucleus is found by E = mc². (b) There is the same number of molecules in equal -volumes of gases. (c) If the temperature of a gas doubles, the pressure doubles. (d) The region surrounding the nucleus has negative charges.arrow_forward
- The accepted value of the melting point of pure aspirin is 135 °C. Trying to verify that value, you obtain 134 °C, 136 °C, 133 °C, and 138 °C in four separate trials. Your partner finds 138 °C, 137 °C, 138 °C, and 138 °C. (a) Calculate the average value and percent error for your data and your partner’s data. (b) Which of you is more precise? More accurate?arrow_forward(1) A rectangular block of wood has the following dimensions: 10.0 cm x 5.00 cm x 4.00 cm. The block weight 100 g. What is the density of the block of wood? (2) What is the mass of a 400-mL sample of ethyl alcohol if its density is 0.8 g/mL?arrow_forwardCalculate the mass of each of these objects.(a) How much mercury, with a density of 13.5939 g/cm3, weighs in at 8.00 cm3?If the density of 45.0 mL octane is 0.702 g/cm3, how much mass does it have?arrow_forward
- A spherical steel ball has a mass of 3.475 g and a diameter of 9.40 mm. What is thedensity of the steel? |The volume of a sphere = (4/3)πr3 where r = radius.]arrow_forward(a) If the proper dose of ibuprofen for a 150.-lb adult is three 200.-mg tablets, calculate the dosage in mg per kg of body weight. (b) How many milligrams of ibuprofen would a 45-kg individual receive if he were given the same dose?arrow_forward(Q1) Which of the following statements is not correct? A) Lab instructors should be notified if you break a thermometer that contains mercury. B) All chemicals in the lab must be treated as hazardous, even chemicals such as NaCl (table salt). C) Fire alarms, fire extinguishers, showers, and emergency eye washes, are examples of safety equipment in the lab. D) Pipettes and droppers shouldn't be inserted into any reagent bottle, even if they are clean. E) If you break a thermometer that contains mercury you can clean it up with a paper towel.arrow_forward
- You are making sandwiches again. This time, one triple-decker sandwich consists of 4 slices of bread, 6 chicken slices, and 3 tomato slices. Suppose that you have 3.84 kg of slices of bread, 3.72 kg of chicken slices, and 1.26 kg of tomato slices.You also know that a dozen slices of bread weigh 360 g, a dozen slices of chicken weigh 240 g, and a dozen slices of tomato weigh 144 g. (One dozen is 12). (a) What is the maximum number of complete sandwiches you can make with the quantities you have available? (b) Which ingredient is the limiting one? (c) What is the mass (in grams) of one sandwich?arrow_forwardName the SI base units that are important in chemistry,and give the SI units for expressing the following:(a) length, (b) volume, (c) mass, (d) time, (e) temperature.arrow_forwardAssess the correctness of each of the statements. TRUE OR FALSE The three states of matter can be interconverted without changing the substance's composition. • A substance is a matter that has indefinite composition but with distinct properties. • Color, melting point, density and boiling point are physical properties of matter • We cannot recover hydrogen and oxygen from water by a physical change like boiling or freezing. • Intramolecular forces hold atoms together in a molecule. • In order to evaporate a liquid, much less energy is needed than to to break the bonds in the liquid's molecules. • Molecules with temporary dipole moment tend to align with opposite polarities in the solid phase for maximum attractive interaction.arrow_forward
Introductory Chemistry: A FoundationChemistryISBN:9781337399425Author:Steven S. Zumdahl, Donald J. DeCostePublisher:Cengage Learning