<span>Dalton's atomic theory originally has 5 postulates. Among the choices, there are three that are included. These are:
*atoms of one element cannot change into atoms of another element.
</span><span>*each element is composed of tiny, indestructible particles called atoms.
</span><span>*atoms combine in simple, whole number ratios to form compounds
The others are incorrect. Atoms of one element cannot change to another element. Atoms of the same element do not have the same mass because they can occur as isotopes. Nuclear particles are not part of Dalton's theory, just the chemical reactions.</span>
Answer:
I <em><u>THINK mechanical energy</u></em>
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.
Like states of matter? A tree is a solid