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skad [1K]
3 years ago
8

In an observational study researchers try not to

Biology
1 answer:
o-na [289]3 years ago
5 0

Answer:

D

Explanation:

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Describe some ways that human activities are affecting aquatic ecosystems. Propose strategies that individuals can use and gover
Art [367]

Answer:

Humans are heavily polluting the waters in many areas with chemicals, medicine (for people), and garbage. A way that the government can help stop this issue is to have groups do routine cleanings of natural bodies of water along with prohibite the use of disposable items in the area like cups and/or bags.

Explanation:

5 0
3 years ago
How many grams of potassium nitrate (KNO3) would form if 2.25 liters of a 1.50 molar lead nitrate Pb(NO3)2 solution reacts with
nekit [7.7K]
First we must understand the balanced chemical equation:
Pb(NO3)2 + K2CrO4 ==> PbCr04 + 2KNO3

This shows us that two moles of potassium nitrate are formed from 1 mole of lead nitrate or potassium chromate solution. The next step is to find out how many moles of each reactant there are. Note the word Molar is a concentration that simply means moles per liter.

2.25L of 1.5M lead nitrate = 2.25x1.5 = 3.375 moles of lead nitrate
1.15L of 2.75M potassium chromate = 1.15x2.75 = 3.1625 moles

The important part here is to see that the number of moles of the reactants are different. We know the number of moles of products will be dependent on the number of moles of reactants, and in this case there is less potassium chromate than there is lead nitrate, so this is the limiting factor as there is a one to one relationship with both reactants. Therefore, the number of moles of potassium nitrate produced is 2 x number of moles of potassium chromate. i.e. 6.325 moles of potassium nitrate is liberated.

To work out the number of grams, we must find the molar mass (the mass of one mole) of KNO3, which is the sum of the molar mass of each of its component atoms that make up the molecule. I've looked this up as 101.1 grams per mole.

Now we simply times the molar mass by the number of moles to yield the final grams liberated: 6.325 moles  x 101.1 grams/mole = 639.4 grams of potassium nitrate is liberated from this reaction.
7 0
3 years ago
Read 2 more answers
What is a major diffrence between facilitated diffusion and active transport
irina [24]

Answer:

Facilitated diffusion require no energy and travels down the gradient of concentration. On the other hand, active transport takes energy and travels up the gradient of concentration.

Hope this helps! Have a great day!!

5 0
3 years ago
Which structure is at work when the body deals with reflex actions?
Ne4ueva [31]

Answer:

spinal cord

Explanation:

Reflex actions are the involuntary action of the body in response to a signal or stimulus. The reflex action of body is controlled by spinal cord.

Reflex arc acts as a neural pathways that transmit impulse to the brain via spinal cord. Sensory neurons pass through synapse in the spinal cord which activate spinal motor neuron to act immediately without any delay.

Immediate taking off hand from hot oven is an example of reflex action, which is regulated by spinal cord.  

Hence, the correct option is spinal cord.

 

5 0
3 years ago
Read 2 more answers
Chapter 13 Active Reading Guide:
Dmitriy789 [7]

Answer:

(A): DNA and protein

(B): The case for proteins appeared stronger until the 1940s, especially since biochemists had identified them as a class of macromolecules with great heterogeneity and function specificity, essential requirements for the hereditary material. Moreover, little was known about nucleic acids, the physical and chemical properties of which seemed far too uniform to account for the multitude of specific hereditary traits of each organism

(C): Virulent strains are pathogenic (causing disease), whereas non-virulent strains are non-pathogenic (harmless) strains.

6 0
3 years ago
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