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bazaltina [42]
3 years ago
12

4. What is the rarest element that is natural to earth?

Chemistry
2 answers:
krek1111 [17]3 years ago
5 0
Astatine it’s also a chemical element
never [62]3 years ago
3 0

Answer:

Astatine

Explanation:

Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements.

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To measure the speed of a car, we use miles per hour (miles/hour or mi/h or mph). To measure the rate of a reaction we use molar
arsen [322]

Answer:

Part A: 47.8 mi/h

Part B: 0.072 M/s

Part C: 0.144 M/s

Explanation:

Part A

The average speed or velocity (V) is the variation of the space divided by the variation of the time:

V = (241 - 2)/(8 -3)

V = 47.8 mi/h

Part B

As Part A, the average rate (r) of formation of I2 is the variation of the concentration divided by the variation of time:

r = (1.83 - 1.11)/(15 - 5)

r = 0.072 M/s

Part C

The rates of the substances are proportional of their number of moles (n) which are their coefficient, so:

rI2/nI2 = rHCl/nHCl

0.072/1 = rHCl/2

rHCl = 2*0.072

rHCl = 0.144 M/s

7 0
3 years ago
What prediction can i make about malaria
Sunny_sXe [5.5K]

Answer:

A disease caused by a plasmodium parasite, transmitted by the bite of infected mosquitoes.

The severity of malaria varies based on the species of plasmodium.

Symptoms are chills, fever, and sweating, usually occurring a few weeks after being bitten.

People traveling to areas where malaria is common typically take protective drugs before, during, and after their trip. Treatment includes antimalarial drugs.

Explanation:

4 0
3 years ago
If a stronger solution of sodium bicarbonate was used in beaker B, would it require more or less acetic acid to neutralize and w
Dmitriy789 [7]

Answer:

A stronger acid is needed to neutralize the reaction.

Explanation:

Neutral pH solutions are because the acid counteracts the effect of the base, and vice versa.

Both chemical products, both acid and base, reach a pH of 7, which indicates the neutrality of the solution in the reaction, that is, the solution is neither acidic nor basic but NEUTRAL.

The higher the alkalinity of the base, the greater the acidity of the acid will be needed to balance and balance the pH to give neutrality as the final product.

3 0
3 years ago
This is a physical combination of one substance dissolved in another.
FinnZ [79.3K]

Answer:

  • <u><em>Solution </em></u><em>is a physical combination of one substance dissolved in another.</em>

Explanation:

A <em>solution</em> is a homogeneous mixture.

The solutions are characterized by uniform composition and one phase, but they can be either solid, liquid or gases.

In a solution there is, at least, one solute <em>substance</em> and one or more solvents.

A typical solution is salt and water: salt is the solute, which is <em>dissolved</em>, in water (the solvent).

In a solution, you can not distinguish visually the solute from the solvent, but, since they are physically, and not chemically, combined, they can be separated by physical media, e.g. evaporation.

6 0
3 years ago
Read 2 more answers
Determine what mass of carbon monoxide and what mass of hydrogen are required to form 6.0 kg of methanol by the reaction CO(g) +
siniylev [52]

Answer:

5250 grams or 5.25 kg of carbon monoxide and 375 grams of hydrogen are required to form 6 kg of methanol.

Explanation:

The balanced reaction:

CO (g) + 2 H₂ (g) -> CH₃OH (l)

By stoichiometry of the reaction, the following amounts of moles of each compound participate in the reaction:

  • CO: 1 mole
  • H₂: 2 moles
  • CH₃OH: 1 mole

Being the molar mass of each compound:

  • CO: 28 g/mole
  • H₂: 1 g/mole
  • CH₃OH: 32 g/mole

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

  • CO: 1 mole* 28 g/mole= 28 grams
  • H₂: 2 moles* 1 g/mole= 2 grams
  • CH₃OH: 1 mole* 32 g/mole= 32 grams

Being 6 kg equivalent to 6000 grams (1 kg= 1000 grams), you can apply the following rules of three:

  • If by stoichiometry 32 grams of methanol are formed from 28 grams of carbon monoxide, 6000 grams of methanol are formed from how much mass of carbon monoxide?

mass of carbon monoxide=\frac{6000 grams of methanol*28 grams of carbon monoxide}{32 grams of methanol}

mass of carbon monoxide= 5250 grams= 5.25 kg

If by stoichiometry 32 grams of methanol are formed from 2 grams of hydrogen, 6000 grams of methanol are formed from how much mass of hydrogen?

mass of hydrogen=\frac{6000 grams of methanol*2 grams of hydrogen}{32 grams of methanol}

mass of hydrogen= 375 grams

<u><em>5250 grams or 5.25 kg of carbon monoxide and 375 grams of hydrogen are required to form 6 kg of methanol. </em></u>

8 0
3 years ago
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