Answer:
radiation and conduction
Explanation:
During a warm summer day, a car became extremely hot. When a student went to open the car door, he burned his fingers. What two forms of energy were responsible for the student burning his fingers?
Solution:
Heat is the transfer of energy from a warmer object to a cooler object. For heat transfer to occur, there have to be a difference in temperature between two objects.
Heat can be transferred in three ways: by conduction, by convection, and by radiation.
Conduction is the transfer of thermal energy between bodies through direct contact. Convection is the transfer of thermal energy through the movement of heat in a liquid or gas. Radiation is the transfer of thermal energy through thermal emission by electromagnetic waves.
During a warm summer day, The sun makes the car to become hot through energy transfer from the sun to the car. When the student touch the car, there is heat transfer as a result of conduction.
C.
This is because the water has undergone a physical change meaning that the effects can be reversed. If nothing was added or lost from the water the ice would be the exact same weight.
Answer:
1. 25 moles water.
2. 41.2 grams of sodium hydroxide.
3. 0.25 grams of sugar.
4. 340.6 grams of ammonia.
5. 4.5x10²³ molecules of sulfur dioxide.
Explanation:
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In this case, since the mole-mass-particles relationships are studied by considering the Avogadro's number for the formula units and the molar mass for the mass of one mole of substance, we proceed as shown below:
1. Here, we use the Avogadro's number to obtain the moles in the given molecules of water:
2. Here, since the molar mass of NaOH is 40.00 g/mol, we obtain:
3. Here, since the molar mass of C6H12O6 is 180.15 g/mol:
4. Here, since the molar mass of ammonia is 17.03 g/mol:
5. Here, since the molar mass of SO2 is 64.06 g/mol:
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Answer:
Chopping wood logs
A pot of water o a grate over a burning fire
Explanation:
Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.
The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.
Explanation:
