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:
- <u><em>Ratio of the mass carbon that combines with 1.00 g of oxygen in compound 2 to the mass of carbon that combines with 1.00 g of oxygen in compound 1 = 2</em></u>
Explanation:
First, detemine the mass of oxygen in the two samples by difference:
- mass of oxygen = mass of sample - mass of carbon
Item Compound 1 Compound 2
Sample 80.0 g 80.0 g
Carbon 21.8 g 34.3 g
Oxygen: 80.0 g - 21.8g = 58.2 g 80.0 g - 34.3 g = 45.7 g
Second, determine the ratios of the masses of carbon that combine with 1.00 g of oxygen:
- For each sample, divide the mass of carbon by the mass of oxygen determined above:
Sample Mass of carbon that combines with 1.00 g of oxygen
Compound 1 21.8 g / 58.2 g = 0.375
Compound 2 34.3 g / 45.7 g = 0.751
Third, determine the ratio of the masses of carbon between the two compounds.
- Divide the greater number by the smaller number:
- Ratio = 0.751 / 0.375 = 2.00 which in whole numbers is 2
The volume of a box with length 25 cm, height 25 cm and width 1.0 m is 0.0625m³.
Volume of the box which is a cuboid can be calculated by multiplying the length, breadth and height of the given box.
Volume of the box is given by the product of the length of the box, Height of the box and Breadth or width of the box.
Since, the box is a cuboid, hence the formula is given by the products of length, breadth and height.
Given,
length of the box= 25cm = 0.25m
Height of the box =25cm = 0.25m
width of the box= 1m
Volume = length × width × height of box
Volume = 0.25 × 0.25 × 1
Volume = 0.0625m³
The volume of the box is 0.0625m³.
Learn more about Volume here, brainly.com/question/23118276
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Answer:
The answer is: D
Explanation:
A. They have the same number of electron energy shells. Is false, all the elements are in different periods so, they have different number of lectron energy shells.
B. They are all Halogens. No, is wrong, halogens are F, Cl ,Br
C. They have the same number of electrons. is wrong, if they had the same number of electrons they must be they same element and they aren't the same.
D. They are all Noble gases. Yes, it's true they are noble gases, they are the first group in the periodic table from the right.
Answer:
There is None
Explanation:
This is because it is a derived function dependent on other factors.