Answer:
B, liquid to solid.
Explanation: Since heat is being released, the particles for H2O would clump up. Heat is basically being taken out.
Answer: The answer is C. A mercury thermometer is better to measure very small changes in temperature.
Explanation:
i took this quiz and this is the answer .
A) A mercury thermometer can measure the freezing point of a liquid that freezes at −80 °C.
B) An alcohol thermometer can measure the boiling point of a liquid that boils at 80 °C.
C) A mercury thermometer is better to measure very small changes in temperature.
D) An alcohol thermometer is better to measure the boiling points of colorless liquids.
It's a physical change because the composition of the salt hasn't change. Only the change in substance/form has occured. To tell if something has undergone physical change is:
• Melting
• Boiling
• Freezing
• Condensing
• Breaking
• Bending
• Dissolving
• Molecules can change motion and proximity
To tell if something changed chemically:
• Molecules rearrange with other molecules to make new substance
• Can be production of flames
• Color change
• Bubbling/fizzing
• Temp. change
• change in composition
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Explanation:
1. Water decomposition
- Decomposition reactions are represented by-
The general equation: AB → A + B.
- Various methods used in the decomposition of water are -
- Electrolysis
- Photoelectrochemical water splitting
- Thermal decomposition of water
- Photocatalytic water splitting
- Water decomposition is the chemical reaction in which water is broken down giving oxygen and hydrogen.
- The chemical equation will be -
Hence, balancing the equation we need to add a coefficient of 2 in front of 
on right-hand-side of the equation and 2 in front of 
on left-hand-side of the equation.
∴The balanced equation is -
→ 
2. Formation of ammonia
- The formation of ammonia is by reacting nitrogen gas and hydrogen gas.
→ 
Hence, for balancing equation we need to add a coefficient of 3 in front of hydrogen and 2 in front of ammonia.
∴The balanced chemical equation for the formation of ammonia gas is as follows -
→ 
.
- When 6 moles of
react with 6 moles of 4 moles of ammonia are produced.
Nitrous oxide has 2 nitrogen atoms and 1 oxygen atom per molecule
