It's 1. Melting a substance. The rest are chemical changes
c. online college and career planning resource you can access once you take the PSAT.
Explanation:
MyRoad is an online platform where college and career planning resources can be accessed when the PSAT has been taken.
It provides an online mentor-ship and guidance for approaching the more robust college life.
The platform allows diverse students to access useful information about their intended colleges.
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Answer:
scale. Mercury thermometers can be used to determine body, liquid, and vapor temperature.
Answer:
D. 7
Explanation:
The halogens are found in Group 7 of the Periodic Table. If Bromine is a halogen, then that means it would be found in Group 7. Also, elements in Group 7 have 7 electrons in its outer shell, Bromine would have 7 electrons in its outer shell.
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Answer:</h3>
Chlorine gas (Cl₂)
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Explanation:</h3>
- According to the Graham's law of diffusion, the diffusion rate of a gas is inversely proportional to the square root of its density or molar mass.
- Therefore, a lighter gas will diffuse faster at a given temperature compared to a heavy gas.
- Consequently, the heavier a gas is then the denser it is and the slower it diffuses at a given temperature and vice versa.
In this case we are given gases, CI₂
, H₂,He and Ne.
- We are required to identify the gas that will diffuse at the slowest rate.
- In other words we are required to determine the heaviest gas.
Looking at the molar mass of the gases given;
Cl₂- 70.91 g/mol
H₂- 2.02 g/mol
He - 4.00 g/mol
Ne- 20.18 g/mol
Therefore, chlorine gas is the heaviest and thus will diffuse at the slowest rate among the choices given.
