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3 years ago

(Please answer as quickly as possible for brainliest, thanks :))

Chemistry

2 answers:

Eddi Din [679]3 years ago

4 0

A. actinides do not occur in nature.

damaskus [11]3 years ago

3 0

Hello,

The answer is option A <span>Actinides.

Reason:

The answer is </span><span>Actinides because they are human made. Its not option B because some of those are minerals. Its not C because gases are caused by nature. Its also not D because nonmetals are also made by nature.

If you need anymore help feel free to ask me!

Hope this helps!

~Nonportrit</span>

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The top is an example problem the bottom one is the one i need help with. I only need C,D, and E please help

velikii [3]

Answer:

correct

Explanation:

makes sense just re-write!

5 0

3 years ago

Read 2 more answers

Which electron configuration of the 4f energy sublevel is most stable?

umka21 [38]

Answer: both options A and D

Explanation:

Half filled and completely filled orbitals are more stable than any other configuration since they are more symmetrical and energy exchange Occurs readily.

So 4f^7& 4f^14 are more stable

7 0

2 years ago

A mixture of methanol and methyl acetate contains 15.0 wt% methanol.

Usimov [2.4K]

The mixture flow rate in lbm/h = 117.65 lbm/h

<h3>Further explanation</h3>

Given

15.0 wt% methanol

The flow rate of the methyl acetate :100 lbm/h

Required

the mixture flow rate in lbm/h

Solution

mass of methanol(CH₃OH, Mw= 32 kg/kmol) in mixture :

$\tt 15\%\times 200~kg=30~kg\\\\mol=\dfrac{mass}{MW}=\dfrac{30~kg}{32~kg/kmol}=0.9375~kmol$

mass of the methyl acetate(C₃H₆O₂,MW=74 kg/kmol,85% wt) in 200 kg :

$\tt 85\%\times 200=170~kg\\\\mol=\dfrac{170}{74}=2.297~kmol$

Flow rate of the methyl acetate in the mixture is to be 100 lbm/h.

1 kg mixture = 0.85 .methyl acetate

So flow rate for mixture :

$\tt \dfrac{1~kg~mixture}{0.85~methyl~acetat}\times 100~lbm/h=117.65~lbm/h$

5 0

2 years ago

When the equation Sn + HNO₃ → SnO₂ + NO₂ + H₂O is balanced in acidic solution, what is the smallest whole-number coefficient for

balu736 [363]

Answer:

Explanation:

Hello,

In this case, for the given reaction we first assign the oxidation state for each species:

$Sn^0 + H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 + N^{4+}O^{2-}_2 + H^+_2O^-$

Whereas the half reactions are:

$Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O$

Next, we exchange the transferred electrons:

$1\times(Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-)\\\\4\times (H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O)\\\\\\Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\4H^++4H^+N^{5+}O^{-2}_3 +4e^-\rightarrow 4N^{4+}O^{2-}_2+4H_2O$

Afterwards, we add them to obtain:

$Sn^0+2H_2O+4H^++4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4H^++4N^{4+}O^{2-}_2+4H_2O$

By adding and subtracting common terms we obtain:

$Sn^0+4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4N^{4+}O^{2-}_2+2H_2O$

Finally, by removing the oxidation states we have:

$Sn + 4HNO_3 \rightarrow SnO_2 + 4NO_2 + 2H_2O$

Therefore, the smallest whole-number coefficient for Sn is 1.

Regards.

6 0

3 years ago

What are the effects on the bodies of water? use terms algal bloom, dead zone and hypotoxic

Anna35 [415]

Water pollution is defined as the mixing of water with unwanted substances and that makes water unsafe.

Water pollution includes runoff of excess fertilizers,

herbicides, and insecticides from agricultural lands

and residential areas; oil, grease, and toxic chemicals

from urban runoff and energy production; and

sediment from improperly managed construction sites,

crop and forest lands, and eroding stream banks.

Polluted waters have high BOD which affects aquatic biodiversity.

Hpotoxic substances such as lead, arsenic, and fluoride cause many problems to aquatic animals and humans. Water contaminated with Arsenic results in diseases such as arsenicosis. Fluoride had been reported to cause depression in DNA and RNA synthesis in cultured cells, significant reductions in DNA and RNA levels, and conditions including aging, cancer, and arteriosclerosis are associated with DNA damage and its disrepair. Lead causes problems related to the central nervous system. Children and pregnant women are most at risk. Routine applications of fertilizers and pesticides for agriculture and uncontrolled runoff in water bodies. Adds nitrogen and phosphorus to water. It adds nitrogen and phosphorus to water causing eutrophication and algal blooms.

Therefore, all these activities make our water bodies a death zone for the marine ecosystem as well as humans.

To know more about water pollution, refer to the below link:

brainly.com/question/2976496

#SPJ4

8 0

1 year ago