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DanielleElmas [232]

3 years ago

15

urgent please help!!!!!! Which factors add to the greenhouse effect and are caused by human activities? Select two options. a de

crease in the amount of dust in the atmosphere a decrease in the amount of water on Earth’s surface an increase in gases in the atmosphere that absorb heat an increase in surfaces that radiate energy into the atmosphere an increase in the amount of solar radiation that reflects into space

1 answer:

Sav [38]3 years ago

4 0

Answer:

I would say that the answers are an increase in gases in the atmosphere that absorb heat an increase in surfaces that radiate energy into the atmosphere, and a decrease in the amount of water on Earth’s surface

Explanation:

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Scientist can use the of minerals to tell them apart A.sound B.length C.size D.color

ipn [44]

Answer:

color

Explanation:

Scientists can use the color of minerals to tell them apart.

7 0

3 years ago

What volume would 56.2 mL of gas at 820 mm of Hg occupy at 720 mm of Hg?

Andreyy89

Answer:

49.35 mL

Explanation:

Given: 56.2 mL of gas

To find: volume that 56.2 mL of gas at 820 mm of Hg would occupy at 720 mm of Hg

Solution:

At 820 mm of Hg, volume of gas is 56.2 mL

At 1 mm of Hg, volume of gas is $\frac{56.2}{820}$

At 720 mm of Hg, volume of gas is $\frac{56.2}{820}(720)=49.35\,\,mL$

3 0

2 years ago

Dissolve 30 g of sodium sulphate into 300 mL of water

Aneli [31]

Answer:

number of moles = 0.21120811

Explanation:

To find the number of moles, given the mass of the solute, we use the formula:

$\mathrm{n = \dfrac{ m }{ M } }$

$\mathrm{n = number\:of\:moles\:(mol)}$

$\mathrm{m = mass\:of\:solute\:(g)}$

$\mathrm{M = molar\:mass\:of\:solute\:( \dfrac{ g }{ mol } )}$

Label the variables with the numbers in the problem:

$\mathrm{n =\:?}$

$\mathrm{m =30\:g }$

$\mathrm{M =\:?\:Calculate\:the\:molar\:mass }$

The first thing we have to do is find the molar mass of sodium sulfate, in order for us to use the formula for finding the number of moles:

Formula for finding the molar mass of sodium sulfate:

$M({ \left Na \right }_{ 2 } { \left So \right }_{ 4 }) = m \left( Na \right) +m \left( S \right) +m \left( O \right)$

For the variables and what they mean are below for finding the molar mass of sodium sulfate:

$\mathrm{M =molar\:mass }$

$\mathrm{m =moles=2\:moles\:for\:Na\:,1\:mole\:for\:S,\:and\:4\:moles\:for\:O}$

$\mathrm{Na =sodium=22.99\:g }$

$\mathrm{S =sulfur=32.06\:g }$

$\mathrm{O =oxygen=16.00\:g }$

Plug the numbers into the formula, to find the molar mass of sodium sulfate:

$M({ \left Na \right }_{ 2 } { \left So \right }_{ 4 }) = m \left( Na \right) +m \left( S \right) +m \left( O \right)$

$\mathrm{Substitute\:the\:values\:into\:the\:formula}$

$M = 2 \left( 22.99 \right) +1 \left( 32.06 \right) +4 \left( 16.00 \right)$

$\mathrm{Multiply\:2\:by\:22.99\:to\:get\:45.98\:and\:1\:by\:32.06\:to\:get\:32.06}$

$\mathrm{M = 45.98+32.06+4\:(16)}$

$\mathrm{Multiply\:4\:by\:16\:to\:get\:64}$

$\mathrm{M = 45.98+32.06+64}$

$\mathrm{Add\:45.98\:and\:32.06\:to\:get\:78.04}$

$\mathrm{M = 78.04+64}$

$\mathrm{Add\:78.04\:and\:64\:to\:get\:142.04}$

$\mathrm{M = 142.04}$

Now that we have found the molar mass, we can calculate the number of moles in the solution of sodium sulfate with the formula:

$\mathrm{n = \dfrac{ m }{ M } }$

$\mathrm{n =\:?}$

$\mathrm{m =30\:g }$

$\mathrm{M = 142.04\:g/mol}$

$\mathrm{Substitute\:the\:values\:into\:the\:formula}$

$\mathrm{n = \dfrac{ 30 }{ 142.04 }}$

$\mathrm{Divide\:142.04\:by\:30\:to\:get\:0.21120811}$

$\mathrm{n = 0.21120811}$

0.21120811 rounded gives you 0.2112

or if you did the problem without decimals

30 grams of sodium sulfate divided by its molecular weight – which we found to be 142 – gives us a value of 0.2113 moles.

3 0

2 years ago

Pls answer the following question for me

Nadya [2.5K]

1. and C.

Terrycot is a fiber that is made by mixing two fibers. Terrycot is a blended fabric made of terylene and cotton. It has better absorbing power as compared to Terylene. Nylon and terylene are produced through condensation polymeriztation.

<em>Hope it helps...</em>

6 0

2 years ago

Read 2 more answers

What is significant about a temperature of 37 degrees Celsius? Explain your answer

andrey2020 [161]

Explanation:

For most folks, a thermometer reading around 98.6 degrees Fahrenheit (37 degrees Celsius) means their body temperature is normal. Now, two scientists have an idea why our bodies, as well as those of most other mammals, consistently run at that temperature : A toasty body temperature helps keep nasty fungal infections at bay.

"One of the mysteries about humans and other advanced mammals has been why they are so hot compared with other animals," said study co-author Arturo Casadevall, professor and chair of microbiology and immunology at Albert Einstein College of Medicine of Yeshiva. "This study helps to explain why mammalian temperatures are all around 98.6 degrees Fahrenheit."

Casdevall's previous work showed that the number of fungal species that can thrive and, therefore, infect an animal declines by 6 percent for every 1.8 degree F (1 C) rise in temperature. This, he claimed, is why reptiles , amphibians and other cold-blooded animals are susceptible to tens of thousands of fungal species, whereas only a few hundred types of fungi can harm humans and other mammals.

3 0

3 years ago