Answer:
A. 8600 J
General Formulas and Concepts:
<u>Thermochemistry</u>
Specific Heat Formula: q = mcΔT
- q is heat (in J)
- m is mass (in g)
- c is specific heat (in J/g °C)
- ΔT is change in temperature (in °C)
Explanation:
<u>Step 1: Define</u>
[Given] <em>m</em> = 1600 g
[Given] ΔT = 214 °C - 202 °C = 12 °C
[Given] <em>c</em> = 0.450 J/g °C
[Solve] <em>q</em>
<u>Step 2: Find Heat</u>
- Substitute in variables [Specific Heat Formula]: q = (1600 g)(0.450 J/g °C)(12 °C)
- Multiply [Cancel out units]: q = (720 J/°C)(12 °C)
- Multiply [Cancel out units]: q = 8640 J
<u>Step 3: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs as our lowest.</em>
8640 J ≈ 8600 J
Topic: AP Chemistry
Unit: Thermodynamics
The substance you would expect to have a low melting point would be carbon dioxide, so the correct answer would be A
Answer:
The total time that Jim needs to change x oil changes and y tire changes is less than 180 min.
The time needed for x oil changes is 12 * x.
The time needed for y tire changes is 18 * y.
The total time is the sum of the above times and needs to be less than 180 that is
12 * x + 18 * y < 180 divide both sides of equation by 6
12/6 * x + 18/6*y < 180/6
2*x + 3*y < 30
2*x < 30 - 3*y divide both sides by 2 to get the inequality for x
x < 30/2 - 3/2*y = 15 - 1.5 y < 15 that is x < = 15
2*x + 3*y < 30
3*y < 30 - 2*x divide both sides by 3 to get the inequality for y
y < 30/3 - 2/3 *x = 10 - 2/3*x < 10 that is y < = 10
Also we can write x + y < x+ 3/2 * y < 15.
Explanation:
Jim's can do not more then 5 oil changes and not more then 10 tire changes or all together she can do not more then 15 total of oil and tire changes.
Becquerel did not discover that the amount of exposure on the paper was proportional to the amount of uranium that was present in the rocks
<h3>What is radioactivity?</h3>
The phenomenon of radioactivity was discovered by the French scientist Henri Becquerel in 1896 when he placed photographic paper in a drawer with some radioactive rocks.
We have to note that Becquerel did not discover that the amount of exposure on the paper was proportional to the amount of uranium that was present in the rocks hence the stetement is false.
Learn more about radioactivity: brainly.com/question/1770619?
The right answer is 2.
The number of protons contained in a nucleus (called an atomic number) is characteristic of a chemical element. For a given atomic number, the number of neutrons defines different "types" of this element: isotopes. The variation of the number of protons of the nucleus of an atom, during a nuclear reaction for example, causes a change of the element studied.
