Answer:

Explanation:
We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.
We will use the following formula to calculate heat energy.

The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.
- ΔT = final temperature - inital temperature
The aluminum block was heated from 23.0 °C to 73.5 °C.
- ΔT= 73.5 °C - 23.0 °C = 50.5 °C
Now we know all three variables and can substitute them into the formula.
- m= 225 g
- c= 0.897 J/g° C
- ΔT= 50.5 °C

Multiply the first two numbers. The units of grams cancel.



Multiply again. This time, the units of degrees Celsius cancel.


The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.

Multiply by the answer we found in Joules.




The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.

Approximately <u>10.2 kilojoules</u> of energy would be required.
Answer:
Acceleration is zero.
Explanation:
The slope of a position time graph gives the velocity of the body.
If the slope is constant means the velocity is constant.
Now, acceleration is the measure of the change in velocity of a body over a given time interval.
So, the acceleration of a body is directly proportional to the change in velocity of the body.
If there is no change in velocity, this means that the acceleration of the body is zero.
Here, the slope is a constant implying that the velocity is a constant. So, there is no change in velocity. This implies that the acceleration is zero for the body in the given time interval.
Thus, if a position time graph has a constant slope, one can infer that the acceleration is zero.
Answer:
The common ion will be di-positive ion.
Explanation:
The ionization energy is defined as the amount of energy needed for removal of most loosely bound electron from an isolated atom in gaseous state.
The low ionization energy shows that the atom is able to give electron easily as after losing electron it may attain noble gas configuration or half filled stability.
Here the first and second ionization energy, both are low suggesting that the element is ready to give two electrons easily to form a di-positive ion however the third ionization energy is high which shows that it will not form tri-positive ion commonly.
Answer:
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With determination and hard work, people can overcome difficult challenges. How do the people of Greensburg, Kansas, and Chicago, Illinois, illustrate this idea? Use details from both texts to support your response. i cant do it
Explanation:
As one moves across a period, from left to right, both the number of protons and electrons of a neutral atom increase. The enhancing number of electrons and protons results in a greater attraction between the electrons and the nucleus. This uplifted attraction pulls the electrons nearer to the nucleus, therefore, reducing the size of the atom.
On the other hand, while moving down a group, there is an increase in the number of energy levels. The enhanced number of energy levels increases the size of the atom in spite of the elevation in the number of protons. In the outermost energy levels, the protons get attracted towards the nucleus, however, the attraction is less due to an increase in the distance from the nucleus.