Epidemiological studies looks into:
A. Trends in exercise
B. Trends in genetics
C. Trends in drug effectiveness
D. Trends in statistics

The heat required to form 1 mole of carbon dioxide from carbon and oxygen is 393.5 kJ/mol.

Enthalpy of formation of a substance is the heat required to form 1 mole of a substance from its reactants.

Carbon reacts with oxygen to produce carbon dioxide.

The enthalpy of formation of carbon dioxide is -393.5 kJ/mol.

Therefore, the heat required to form 1 mole of carbon dioxide from carbon and oxygen is 393.5 kJ/mol.

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Answer:

the answer is atmospheric carbon dioxide

Explanation:

The presence of carbon dioxide in atmosphere warms the planet and causes the climate change. Human activities have raised the atmospheric CO₂ content. Here atmospheric carbon dioxide is the planetary health measures which humans already exceeded. The correct option is C.

The planetary health measures offers a way to understand the relationship between human health and the environmental sustainability. The global environmental degradation and climate change threaten the foundation of human health and well being.

Carbon dioxide is an important greenhouse gas that comes from the burning of fossil fuels like coal or oil which traps heat. The increased level of CO₂ in the atmosphere causes greenhouse effect and it does not allow hot rays of the sun to escape from the atmosphere.

The increased level of CO₂ also causes the global warming which increases the temperature of the earth.

Thus the correct option is C.

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0.72 L and 2.28 L of 1/5 M and 1/8 M HCl solution are required respectively to obtain 3 L of 1/7 M HCl.

The concentration of a solution is the amount of substance a given volume of the solution of that substance.

The final concentration and volume of the mixture is 3 L of 1/7 M HCl.

Let the volume of 1/5 M and 1/8 M HCl solution required be X and Y respectively.

X + Y = 3 L

Liters of y = 3 -

[.0.2 X + 0.125 * (3-X)] / 3 = 1/7

(0.2X + 0.375 - 0.125X) / 3 = 1/7

(0.075 X / 3) = 1/7 - 0.375/3

(0.075X / 3) = 0.018

Multiplying both sides by 3

0.075 X = 0.054

X = 0.72 L

Y = 2.28 L

Therefore, 0.72 L and 2.28 L of 1/5 M and 1/8 M HCl solution are required respectively.

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Answer:

Yes. Diesel works the best.

Explanation:

Homemade Napalm can be made using the following procedures; Using an enormous container, fill it about halfway with gasoline. Which means Diesel works the best. Break the special soap, Styrofoam(polystyrene), plate into small pieces.

The required moles of AgBr precipitate produced by given moles of silver nitrate is 0.0123.

Molarity of any solution is define as the moles of solute present in per liter of the solution and it will be represented as:
M = n/V

Given that, molarity of AgNO₃ = 0.250M

Volume of AgNO₃ = 49.5mL = 0.0495L

Moles of AgNO₃ = (0.25)(0.0495) = 0.0123mol

Given chemical reaction is:

2AgNO₃(aq) + CaBr(aq) → 2AgBr(s) + Ca(NO₃)₂(aq)

As it is mention that CaBr is present in excess quantity and AgNO₃ is the limiting reagent so the formation of precipitate will depend on the AgNO₃.

From the stoichiometry of the reaction, it is clear that:

2 moles of AgNO₃ = produces 2 moles of AgBr

0.0123 moles of AgNO₃ = produces 2/2×0.0123=0.0123 moles of AgBr

Hence 0.0123 is the required moles of precipitate.

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Answer:

third point

Explanation:

omniscient because it gives info about every character instead of one  

hope this helps

Answer: Option A

Explanation:

Increase in temperature will  increase the yield of the product and cause a shift to the right.

This is the type of reaction in which reactants absorb heat energy from the surroundings to form products.

This depicts that an increase in temperature will increase the yield of products thereby making option A the most appropriate choice.

Explanation:

Hope it helps...

Answer:

H2o,hydrogen,carbonoxide

The current passing through the inductor is 3.8 A. The correct option is D. 3.8 A

From the question, we are to determine the current passing through the inductor.

From the formula, for the energy stored in a magnetic field

E = 1/2LI²

Where E is the energy

L is the inductance

and I is the current

From the given information,

E = 3.6 J

L = 0.50 H

Putting the parameters into the formula, we get

3.6 = 1/2 × 0.50 × I²

3.6 = 0.25 × I²

I² = 3.6 ÷ 0.25

I² = 14.4

I = √14.4

I = 3.7947

I ≅ 3.8 A

Hence, the current passing through the inductor is 3.8 A. The correct option is D. 3.8 A

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Molar mass of 2H2, O2 and 2H2O is 4g, 32g and 36 g per moles respectively.

That is , 4g of H2 = 36g of water

250g of H2 = xg of water

Make xg the subject of formula,

xg = 250× 36/4

xg = 9000/4

xg = 2250g of water

Molar mass of 2H2, O2 and 2H2O is 4g, 32g and 36 g per moles respectively.

32g of oxygen = 36g of water

250g of oxygen = xg of water

Make xg the subject of formula,

xg = 250 × 36/32

xg = 9000/32

xg = 281.25g of water

C3H8(g)+5O2(g)→3CO2(g)+4H2O(g).

Molar mass of propane and water is 44g and 72g per mole.

if 44g of propane = 72 g of water

xg of propane = 1000g of water

make xg the subject of formula,

xg = 44 × 1000/72

xg = 44000/72

xg = 611g of propane

2 H2O → 2H2 + O2

Molar mass of 2H2O and 2H2 is 36g and 4g respectively.

If 36g of water = 4g of Hydrogen

xg of water = 150 g of hydrogen

Make xg the subject of formula,

xg = 36×150/4

xg = 5400/4

xg = 1350g of water

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Answer:

When comparing two ions, gaining the same electrons, atomic radii, you can follow the same general rule as regular ionic radius.

Explanation:

In general, Sulfur has a larger atomic radius than Oxygen, as it is lower on the periodic table. Since they both are gaining the same amount of electrons, the trend still applies

Natural resources are the resources that are generated and found in nature. Water, wood, sunlight, and wind are renewable sources of energy.

Renewable sources of energy are the resources that replenish after depletion over time and are not limited in amount. They get reloaded through the natural process over finite time.

Wind or the air, sunlight from the sun, water, and wood from trees are some examples of renewable sources of energy.

Non-renewable sources of energy are the resources that cannot be easily replenished by natural means after overconsumption as the process of the formation takes hundreds of billions of years.

Oil, natural gases, coal, uranium, and metal ores are nonrenewable sources of energy.

Therefore, natural resources can be renewable or non-renewable.

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Answer:

straight to the point:

Explanation:

atomic radius of :

k = 280 pm

Ca = 231 pm

Mg = 173 pm

Be = 153 pm

Rb = 248 pm

pm means "picometers".

so knowing this we will have :(largest to smallest),

k

Rb

Ca

Mg and

Be.

hope this helps .

Answer:

see below

Explanation:

K.E. = 1/2 * m * v^2

      = 1/2 * 2 * 5^2     j

Answer:

The problem provides you with the solubility of potassium chloride,

KCl

, in water at

20

∘

C

, which is said to be equal to

34 g / 100 g H

2

O

.

This means that at

20

∘

C

, a saturated solution of potassium chloride will contain

34 g

of dissolved salt for every

100 g

of water.

As you know, a saturated solution is a solution that holds the maximum amount of dissolved salt. Adding more solid to a saturated solution will cause the solid to remain undissolved.

In your case, you can create a saturated solution of potassium chloride by dissolving

34 g

of salt in

100 g

of water at

20

∘

C

.

Now, your goal here is to figure out how much potassium chloride can be dissolved in

300 g

of water at this temperature. To do that, use the given solubility as a conversion factor to take you from grams of salt to grams of water

Answer:

.853 M

Explanation:

(72.1 g / 342.3 g/mole) / (246.8 ml /1000 ml/l )= .853 M

Answer:

The number of molecules in 16 grams of oxygen gas is 3.01*10^23, equal to half of Avogadro's number

Explanation:

Answer:

A. Low pressure system

Explanation:

A low pressure system allows for more cloud development. I think of it as in, since the clouds have low pressure on them they can do whatever they want but if the clouds have a high pressure on them, they tend to not do much and most of the time not even form.  

I hope this helps, good luck :)

Answer:

An innate, typically fixed pattern of behavior in animals in response to certain stimuli.

Identified substance which is present in the sample of 55.5g is calcium, because the calculated and actual specific heat is almost same.

Relation between the amount of absorbed heat and specific heat of any substance is shown by following equation:

Q = mcΔT, where

On putting all these values on the above equation, we get

c = 500 / (55.5)(14) = 0.643 J/g. degrees Celsius

And this value is almost equal to the given specific heat value of calcium, so the given substance is calcium.

Hence the given unknown substance is calcium.

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Answer:

1. yes

2. yes

3. no

sorry if wrong but hope this helps

Answer:

Leeches

Explanation:

leeches secrete peptides and proteins that work to prevent blood clots

Answer:

Leeches

Explanation:

They aren't as commonly used as they may have been in places such as ancient Rome or Egypt. But leeches are still used today, even in procedures such as microsurgery. Leeches secrete polypeptides and enzymes that work to prevent blood clots. So they can be useful when it's crucially necessary to avoid bloodclots during a procedure.

Density for 98% = 1.84 g/mL

V M = # mol

0.1 L x 1 M = 0.1 mol

0.1 mol x 98 g/mol = 9.8 g

m =%CDV

9.8 g = 0.98 x 1.84V

V = 5.43 mL

take this volume and carefully (acid to ater) dilute till 100 mL

Answer:

The actual yield is 38.59g of NaCl

Explanation:

Balanced equation: 2Na+CI2-->2NaCl

actual yield= (percent yield*theoretical yield)/100

Theoretical yield= 

17.25*(1/22.989769)*(2/2)*(58.442769)=43.8515

43.8515*0.88=38.59 grams of NaCl

The actual yield is 38.59g of NaCl

The theoretical yield of the reaction is obtained as 43.87 g. The percentage yield is given 88%. Then, the actual yield is 38.6 g.

The percentage yield in a reaction is the  ratio of actual yield to the theoretical yield multiplied by 100. The balanced chemical equation equation of the reaction is :

[tex]\rm 2Na + Cl _{2} \rightarrow 2NaCl[/tex]

Atomic mass of Na = 23 g

2 Na = 46 g

molar mass of NaCl = 58.5 g

2 NaCl = 117 g.

46 g of sodium metal gives 117 g of NaCl. Hence, the mass of NaCl produced from 17.25 g of Na is :

(17.25 × 117) /46 = 43.87 g

Thus the theoretical yield of the reaction is 43.87 g.

The percentage yield  = 88%

Hence, actual yield / theoretical yield  = 0.88

Actual yield = 0.88 × 43. 87 = 38.6 g.

Therefore, the actual yield of the reaction is 38.6 g.

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I would perfer to prefer to live my dream forever because I wouldn't let someone be stuck with my dream forever because I would rather tourture my self other than to toutour everybody else.

I would rather let everyone else live their dream, because living a dream forever after a certain point would get boring, no matter how fun it seems. Additionally, just because I sacrifice me having my dream doesn't mean I wouldn't be able to enjoy life. It just means that I wouldn't be able to live out my best scenario.