The answer should be "by convection" not by radiation.
Answer: An atom in an excited state contains more of kinetic energy than the same atom in the ground state.
Explanation:
Kinetic energy is the energy acquired by an object due to its motion. And, thermal energy is the internal energy of an object arisen because of the kinetic energy present within the molecules of the object.
Potential energy is the energy acquired by an object due to its position.
The total energy present at the center of mass of an object is known as mass-energy.
So, when an atom gets excited then it means it is gaining kinetic energy due to which it moves from its initial position after getting excited.
Thus, we can conclude that an atom in an excited state contains more of kinetic energy than the same atom in the ground state.
<span>From the above given choices :
melting is an endothermic process</span>
Answer:
Specific heat of alloy = 0.2 j/ g.°C
Explanation:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Given data:
Mass of bold = 25 g
Heat absorbed = 250 J
Initial Temperature = 25°C
Final temperature = 78°C
Specific heat of alloy = ?
Solution:
Change in temperature:
ΔT = 78°C - 25°C
ΔT = 53°C
Now we will put the values in formula.
Q = m.c. ΔT
250 j = 25 g × c ×53°C
250 j = 1325 g.°C × c
250 j / 1325 g.°C = c
c = 0.2 j/ g.°C
<h2>Question no 1:</h2><h2>Answer:</h2>
The correct answer is option A which is Sarah is correct because genetic diversity occurs over a long period of time.
<h3>Explanation:</h3>
- Genetic diversity is a large number of allelic combinations for a trait in specie in a population.
- Genetic diversity is caused due to mutations or random breeding in a specie.
- It is good for the adaptation of specie in an environment, due to diverse in genotypes and phenotype of a trait.
<h2>Question number 2:</h2><h2>Answer:</h2>
The correct answer is option B which is the species will adapt to the changes.
<h3>Explanation:</h3>
- Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
- For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
- If the environment changes, the first thing a specie do is an adaptation to that change in the environment.
<h2>Question 3.</h2><h2>Answer:</h2>
The correct answer is option D which is, "The spines of a cactus protect it from animals".
<h3>Explanation:</h3>
- Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
- For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
- So the plant of cactus was in danger due to animals. So the start growing spines in response to animals.
- Hence the correct answer is option D.
<h2>Question 4.</h2><h2>Answer:</h2>
The correct answer is option B which is, "Marie's plant will lean toward the sun so that it can get the most sunlight".
<h3>Explanation:</h3>
- The plant will lean towards the sun light by the mechanism of phototropism.
- Phototropism is the mechanism of growth of the plant in a specific direction in the response of light.
- There are two types of phototropism.
- One is a positive phototropism in which plant grows towards the light.
- The other is negative phototropism in which plant grows away from the light.
- In this question,the plant will do positive tropism.
<h2>Question no. 5</h2><h2>Answer:</h2>
The correct answer is option B which is, "The dodo bird could not adapt quickly to the challenges of the environment".
<h3>Explanation:</h3>
- Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
- For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
- So the dodo could not adopt to the environment. For the positive adaption of survival, they should be afraid of sailors but the would not afraid of a sailor.
- Due to which they went extinct.
Remaining questions are in attached document.
