Answer:
20.4081633 or 20.408
Explanation:
These ones you can do the regular method but it takes to long just divide and shoot.Hope this helps.
Answer:
The correct answer is 281.39 grams.
Explanation:
To arrive at this answer you must first keep in mind the basic equation:
<em>Q = m*Cp* ΔT</em>
Now, in order to calculate the necessary aluminum mass that absorbs 2138 J when passing from 14.83 to 23.31 ° C you must "clear" <em>m</em> of the previous equation.
This means, leave only the mass on one side of the equation, and "pass" <em>Cp</em> and <em>ΔT</em> to the other side dividing <em>Q</em>. This would look like this:
m= Q/ (Cp*ΔT)
Then, <u>you need the value of specific heat of aluminum</u> in the correct units, that is J / g ° C, the approximate value is 0.896.
ΔT is calculated by doing the mathematical operation:
23.31 °C - 14.83 °C = 8.48 °C
<em>
Finally, the values of: Q (data provided in joules), Cp (J / g ° C) and ΔT (calculated in ° C) are replaced in the last equation and the mass (in grams) is calculated resulting in 281.39 grams.</em>
Answer: An element with the same number of protons, but a different number of neutrons
Explanation:
The # of protons in an atom is what determines what atom it is (hydrogen has 1 proton, helium has 2 protons, etc ...). You cannot change the number of protons in an atom without changing what element the atom is.
The number of electrons in atoms varies greatly because electrons are constantly gained, lost, and shared during chemical reactions.
An isotope is a variation of the same element (so they must have the same # of protons) that have different masses (and therefore a different number of neutrons).
The answer is the fourth choice, "An element with the same number of protons, but a different number of neutrons"
<span>The noble gases are a group of chemical elements that make up Group 18
on the periodic table. These gases all have similar properties under
standard conditions: they are all odorless, colorless, monatomic gases
with very low chemical reactivity.</span>
