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Law Incorporation [45]
4 years ago
8

NEED NOW!

Chemistry
2 answers:
Ann [662]4 years ago
7 0

A. a Community - apex



vfiekz [6]4 years ago
6 0
It's either genus or species. I'd go with Genus
You might be interested in
Which of the following would not be considered renewable forms of energy?
sertanlavr [38]

Answer : The correct answer is A. Nuclear reactors using Pu-239

B. burning coal

The sources which are not renewable are known as "non- renewable sources of energy .

Non - renewable sources are those which get expired after rapid use and can never be reproduced . These sources replenishes in very long time . Examples : Coal , petrol or fuels etc .

1) Nuclear reactors using Pu-239 : Nuclear reactors uses radioactive elements like uranium , plutonium etc , which are present in limit . after frequent use of these elements , they will vanish off , Hence we can say nuclear reactors are Non renewable source of energy .

2) Burning coal : Coal is used as one of the major source of fuel . On rapid utilization of coal they will finished from earth . It takes thousand of year for formation of coal . Hence , it is a Non -renewable source .

3) Photo-voltaic cell: These are cells which used solar energy . Solar energy is obtained from sun . Hence solar energy is renewable source of energy so is the photo voltaic cell .

4) Geothermal energy : Geothermal energy is source of energy that is extracted from earth's thermal energy . Since thermal energy of earth is present in very large amount and can be reproduced , hence it renewable source of energy .

5)Wind energy : Wind energy is source of energy that is obtained from wind. And wind is renewable source so the wine energy too .

Consequently , we can say only two of them " Nuclear reactors and burning of coal " are Non renewable force of energy .

3 0
3 years ago
In which two types of reactions do opposite chemical changes occur
RideAnS [48]

Hello!

Before I can answer your question we need to know the different types of chemical reactions that can occur:

  • Single Replacement
  • Double Replacement
  • Synthesis
  • Decomposition
  • Combustion

Combustion is an answer that can usually be ruled out unless oxidation is occuring in the chemical equation (hyrdrogen occuring with oxygen to react)

Synthesis reaction, also known as a Combination reaction, is when the reactants combine to form a single product.

Decompostion is when a single reactant is deconstructed to form multiple products, or the opposite of Synthesis.


With these definitions alone, since they are opposite types of reactions, the answer would be Synthesis and Decomposition reactions !

Hope this helps and if you need anymore clarification feel free to ask.


4 0
3 years ago
What is the pH of a solution prepared by mixing 100.00 mL of 0.020 M Ca(OH)2 with 50.00 mL of 0.100 M NaOH? Assume that the volu
klemol [59]

Answer:

The pH of the solution is 12.78.

Explanation:

The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution. The pOH is defined as the negative logarithm of the activity of the hydroxide ions. That is, the concentration of OH- ions:

pOH= - log [OH-]

On the other side, Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume. Molarity is calculated as:

Molarity= \frac{number of moles}{volume}

Molarity is expressed in units: \frac{moles}{liter}

In this case, the solution is prepared by mixing 100 ml (equal to 0.1 L, where 1000 mL = 1 L) of Ca(OH)₂ 0.020 M with 50 ml (equal to 0.05 L) of 0.100 M NaOH. Then, Ca(OH)₂ and NaOH are strong bases, so they dissociate completely. In the case of the first hydroxide, for each mole of Ca(OH)₂,

form two moles of OH-. In the case of sodium hydroxide, for each mole of hydroxide, one mole of OH- is formed. So, taking into account the definition of molarity, the number of moles of OH- that each hydroxide contributes to the solution is calculated as:

From Ca(OH)₂: 0.1 L* 0.02 M*2 = 0.004 moles

From NaOH: 0.05 L* 0.1 M= 0.005 moles

So, the amount of total moles of OH- is the sum that each hydroxide contributes to the solution: 0.004 moles + 0.005 moles= 0.009 moles

On the other hand, volumes are additive. Then: 0.1 L +  0.05 L= 0.15 L

Replacing in the definition of molarity the number of moles and the volume:

[OH-]=\frac{0.009 moles}{0.15 L}

Solving:

[OH-]= 0.06 \frac{moles}{liter}

Replacing in the definition of pOH:

pOH= - log 0.06

pOH= 1.22

The following relationship can be established between pH and pOH:

pH + pOH= 14

Being pOH= 1.22 and replacing:

pH + 1.22= 14

pH= 14 - 1.22

pH= 12.78

<u><em>The pH of the solution is 12.78.</em></u>

7 0
3 years ago
Name three sources of atmospheric carbon dioxide.
quester [9]

The answer is decomposition, ocean release and respiration. hope this helps u :D

4 0
3 years ago
Which property would cesium most likely have?
Romashka-Z-Leto [24]
The answer is a because its not low ductile or gasst

8 0
3 years ago
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