Answer:
Environmental Changes
Explanation:
Over time, a species will adjust to the changes in environment in order to survive.
Answer:
99.24%.
Explanation:
- NaCl reacted with AgNO₃ as in the balanced equation:
<em>NaCl + AgNO₃ → AgCl(↓) + NaNO₃,</em>
1.0 mol of NaCl reacts with 1.0 mol of AgNO₃ to produce 1.0 mol of AgCl and 1.0 mol of NaNO₃.
- We need to calculate the no. of moles of AgCl produced:
no. of moles of AgCl = mass/molar mass = (2.044 g)/(143.32 g/mol) = 0.0143 mol.
- Now, we can calculate the no. of moles of NaCl that can precipitated as AgCl (0.0143 mol), these moles represents the no. of moles of pure NaCl in the sample:
<em>using cross multiplication:</em>
1.0 mol of NaCl produce → 1.0 mol of AgCl, from the stichiometry.
∴ 0.0143 mol of NaCl produce → 0.0143 mol of AgCl.
- Now, we can get the mass of puree NaCl in the sample:
mass of pure NaCl = (no. of moles of pure NaCl)(molar mass of NaCl) = (0.0143 mol)(58.44 g/mol) = 0.8357 g.
∴ The percentage of NaCl in the impure sample = [(mass of pure NaCl)/(mass of the impure sample)] x 100 = [(0.8357 g)/(0.8421 g)] x 100 = 99.24%.
Answer:
d. 75 protons, 110 neutrons
Explanation:
In an isotope, the number next to the number of the atom is the mass number (Protons + neutrons). Rhenium has as atomic number 75, that means Rhenium has <em>75 protons</em>. As atomic mass, 185, is the sum of protons and neutrons, number of neutrons is:
185 - 75 = <em>110 neutrons</em>
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Thus, right answer is:
<em>d. 75 protons, 110 neutrons
</em>
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Answer:
its particles slow down and come closer together.
Please mark me brainiest!
The reason why you don’t see solid or liquid oxygen is because oxygen is a natural occurring gas. Gas can not be solid or liquid because there is too much energy to have volume/shape. That’s why you see oxygen tanks, as the tank keeps the gas contained and that is why you can’t see it in the air outside or in something like H20 (water).
Hope this helps :)
Just don’t open the link in the other answer. It’s a scam...
