Answer:
I have that same photo (I always where that combo lol)
Explanation:
In contrast to normal cells, cancer cells don't stop growing and dividing, this uncontrolled cell growth results in the formation of a tumor. Cancer cells have more genetic changes compared to normal cells, however not all changes cause cancer, they may be a result of it.
Answer:
- <em>Stored chemical energy is converted to mechanical energy.</em>
Explanation:
A <em>battery</em> posses <em>chemical energy</em>: this is chemical potential energy, which means that it is stored in the chemical bonds of the compounds in the battery. When the compounds in the battery react some bonds are broken and others are formed; at the end some energy is released and electricity is produced.
So, the chemical energy is first transformed into electrical energy.
A motor in the toy is able to transform that electrical energy into motion of gears and axes, which is how the wheels can spin. This motion of gears, axes and wheels is mechanical energy (kinetic energy).
Then, as you see, in that way the stored chemical energy in the battery is transfered to mechanical energy of the toy as it <em>rolls across the floor</em> thanks to the spin of the wheels.
20 B203(s) + 12180 HF(l) = 4060 BF3(g) + 609 H20(l)
Answer:
Its atomic number is 14 and its atomic mass is 28. The most common isotope of uranium has 92 protons and 146 neutrons. Its atomic number is 92 and its atomic mass is 238 (92 + 146).
Answer:
- The option <u><em>B) Fe₂O₃ (s) + 3C(s) → 2Fe(s) + 3CO₂(g),</em></u> because the reactants are only solid units and the products contain gas molecules.
Explanation:
A <em>positive entropy change</em> means that the entropy of the products is greater than the entropy of the reactants.
Entropy in a measure of the radomness or disorder of the system.
Let's see every reaction:
<u />
<u>A) 4NO₂ (g) + 2 H₂O (l) + O₂ (g) → 4 HNO₃ (aq)</u>
Since 5 molecules of a gas (high disorder) combines with 2 molecules of liquid to produce 4 units of aqueous HNO₃ you may expect that the product is more ordered than the reactants, which means that the change in entropy is negative (the entropy decreases).
<u />
<u>B) Fe₂O₃ (s) + 3C(s) → 2Fe(s) + 3CO₂(g)</u>
The left side (reactants) show only solid substances which is a highly ordered arrangement while the right side (products) show the formation a solid (ordered arrangement) and a gas (highly disoredered arrangement), so you can predict the increase of the system entropy, i.e. a positive entropy change.
The <u>equation C)</u> shows the combination of 12 gas molecules to produce 1 solid and 6 gas molecules, so you can expect that the entropy will decrease, i.e. a negative entropy change.
For <u>equation D)</u> the products include solid and gas reactants while the product is just one unit of solid substance, letting you to predict a negative entropy change.
