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3 years ago

I never see anyone with this question

Chemistry

2 answers:

Andreas93 [3]3 years ago

8 0

no hablo ingles <em><u>jajajajjajajajajabbbbbhuuuuuuu</u></em>

ziro4ka [17]3 years ago

4 0

Answer:

i cant see the pic

Explanation:

You might be interested in

PLEASE HELP WILL MARK BRAINLIEST ! Where did the mass of the forest trees come from? What happens to that mass when the forest b

Oxana [17]

Answer:

it is a flat mass

Explanation:

Because it was used up.

3 0

4 years ago

The radioisotope phosphorus-32 is used in tracers for measuring phosphorus uptake by plants. The half-life of phosphorus-32 is 1

Harman [31]

Answer:

54 days

Explanation:

We have to use the formula;

0.693/t1/2 =2.303/t log Ao/A

Where;

t1/2= half-life of phosphorus-32= 14.3 days

t= time taken for the activity to fall to 7.34% of its original value

Ao=initial activity of phosphorus-32

A= activity of phosphorus-32 after a time t

Note that;

A=0.0734Ao (the activity of the sample decreased to 7.34% of the activity of the original sample)

Substituting values;

0.693/14.3 = 2.303/t log Ao/0.0734Ao

0.693/14.3 = 2.303/t log 1/0.0734

0.693/14.3 = 2.6/t

0.048=2.6/t

t= 2.6/0.048

t= 54 days

3 0

3 years ago

How many milliliters of a 3.4 M NaCl solution would be needed to prepare each solution?

Ksenya-84 [330]

Answer:

a. Approximately $1.3\; \rm mL$ .

b. Approximately $7.2\; \rm mL$ .

Explanation:

The unit of concentration " $\rm M$ " is equivalent to " $\rm mol \cdot L^{-1}$ ", which means "moles per liter."

However, the volume of both solutions were given in mililiters $\rm mL$ . Convert these volumes to liters:

$\displaystyle 45\; \rm mL = 45\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.045\; \rm L$ .

$\displaystyle 330\; \rm mL = 330\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.330\; \rm L$ .

In a solution of volume $V$ where the concentration of a solute is $c$ , there would be $c \cdot V$ (moles of) formula units of this solute.

Calculate the number of moles of $\rm NaCl$ formula units in each of the two solutions:

Solution in a.:

$n = c \cdot V = 0.045\; \rm L \times 0.10\; \rm mol \cdot L^{-1} = 0.0045\; \rm mol$ .

Solution in b.:

$n = c \cdot V = 0.330\; \rm L \times 0.074\; \rm mol \cdot L^{-1} = 0.02442\; \rm mol$ .

What volume of that $3.4\; \rm M$ (same as $3.4 \; \rm mol \cdot L^{-1}$ ) $\rm NaCl$ solution would contain that many

For the solution in a.:

$\displaystyle V = \frac{n}{c} = \frac{0.0045\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0013\; \rm L$ .

Convert the unit of that volume to milliliters:

$\displaystyle 0.0013\; \rm L = 0.0013\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 1.3\; \rm mL$ .

Similarly, for the solution in b.:

$\displaystyle V = \frac{n}{c} = \frac{0.02442\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0072\; \rm L$ .

Convert the unit of that volume to milliliters:

$\displaystyle 0.0072\; \rm L = 0.0072\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 7.2\; \rm mL$ .

8 0

3 years ago

Changes in the composition of the atmosphere have caused gradual changes in earth's _______ throughout history, causing changes

bearhunter [10]

climate

Changes in the composition of the atmosphere have caused gradual changes in earth's <u>climate</u> throughout history, causing changes in plant and animal life that contributed to mass extinctions.

The following are some of the reasons:

UV light
climate
pollutants
hydrofluorocarbons

heat

The surface of the Earth warms up as sunlight strikes it.
Surface-emitted infrared light is absorbed in the atmosphere and transformed into heat.
The temperature close to the surface rises as a result of this heat being trapped in the atmosphere.

<h3>UV light:</h3>

indirect impacts of climate change on UV radiation from the surface.
By changing the concentrations of ozone, UV-absorbing tropospheric gases, aerosols, and clouds in the atmosphere, climate change may have indirectly affected UV radiation levels in the past.
These influences are probably going to persist in the future.

<h3>climate:</h3>

People are at risk from food and water shortages, greater flooding, high heat, an increase in disease, and economic loss due to climate change.
Conflict and human migration are potential outcomes.
Climate change is the top hazard to world health in the twenty-first century, according to the World Health Organization (WHO).

<h3>pollutants:</h3>

these are also resulting in the increase of temperature of the Earth and is also damaging ozone layer.

To learn more about the changes in earth visit:

brainly.com/question/13434833?

#SPJ4

6 0

1 year ago

What would happen to earth's orbit around the sun if there were gravity

kipiarov [429]

If the sun was not there the earth would travel in a straight line

7 0

4 years ago