Here are the answers to your questions:
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What is true about a scientific idea?
- It can be observed and tested.
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What is a scientific method?
- A system for conducting a scientific investigation.
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Which of the following is usually done first in the scientific method of investigation?
- Ask a question based on an observation.
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Which step of the scientific method did Melanie do here?
- Testing with an experiment.
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What does the mass of an object depend on?
- Amount of matter that makes up the object.
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What quantities are these most likely describing?
- Quantity A is mass and Quantity B is weight.
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Which statement is correct?
- The weight of an object will be greater on Earth than Mars.
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How is density calculated given mass and volume?
- Mass divided by volume.
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Which of the following is a unit of volume of liquids?
- Liters.
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Which object has a greater volume and by how much?
- Object A, by 1.6 cubic centimeters. (Volume of Object A = Mass/Density = 12g / 3g/cm³ = 4 cm³; Volume of Object B = 12g / 5g/cm³ = 2.4 cm³; 4 cm³ - 2.4 cm³ = 1.6 cm³.)
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What is the mass of the cube?
- 160 g. (Volume = \( \text{Length}^3 = 2cm \times 2cm \times 2cm = 8cm³ \); Mass = Density x Volume = 40g/cm³ x 8cm³ = 320g.)
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What best describes the temperature at which a solid turns into a liquid?
- Melting point.
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Which of the following is an intensive property?
- Magnetism.
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Which substances have high thermal conductivity?
- Iron and Aluminum.
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Why is Sue's table incorrect?
- Air is a good conductor of heat. (The statement is misleading; air is generally a poor conductor, but wax, if present, acts as an insulator in the context of heat transfer in this experimental setup.)
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What was the independent variable in this experiment?
- Type of wire used.
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Part 1: Is the value of Q less than, greater than, or equal to the value of P?
- The value of Q is greater than the value of P. Part 2: Explain your answer for Part 1.
- Since density is calculated as mass divided by volume (Density = Mass/Volume), and mass is constant for both substances (200 g), if iron has a higher density than silver (7.8 g/cm³ for iron versus 19.3 g/cm³ for silver), then the volume occupied by 200 g of silver (which is less dense) will be less than that occupied by iron. Thus, Q, representing the density of silver at 200 g, must be less than P, which is the density of iron at the same mass.
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Part 1: Which substance has a higher solubility?
- Substance A has a higher solubility. Part 2: Explain your answer for Part 1.
- Substance A shows a significant decrease in the amount of undissolved substance as the temperature increases (from 12 g at 20 °C to 8 g at 80 °C), indicating that it dissolves more readily in water as temperature increases. In contrast, Substance B, while it does show a decrease in undissolved mass, still leaves a higher amount undissolved compared to Substance A across all temperatures measured, demonstrating that Substance A has a higher overall solubility.