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2 years ago

Which two practices are examples of how people use sciense

Chemistry

1 answer:

Semenov [28]2 years ago

6 0

Answer: A: Explaining natural events using facts and data AND B:Developing theories using many lines of evidence

Explanation: trust me.

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Which of the following represents radiant energy being converted to chemical energy?

Arte-miy333 [17]

ANSWER

The correct answer is A

EXPLANATION

Plants manufacture their on food by the process of photosynthesis. During this process, plants trap radiant energy from the sun by the help of chlorophyll in the leaves.

Radiant energy with other raw materials such as water, carbon dioxide and mineral salts is converted to food (in the form of starch) which contains chemical energy.

6 0

3 years ago

A certain first-order reaction has a half-life of 20.0 minutes. How much time is required for this reaction to be 75% complete?

ryzh [129]

Answer:

X = 2

Explanation:

As you know, the rate of a first-order reaction depends linearly on the concentration of a single reactant. The rate of a first-order reaction that takes the form

3 0

2 years ago

Iron is extracted from iron oxide in the Blast Furnace: Fe 2 O 3 + 3 CO → 2 Fe + 3 CO 2

arsen [322]

a. mass of iron = 69.92 g

b. percent yield = 93%

<h3>Further eplanation </h3>

Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated

General formula:

Percent yield = (Actual yield / theoretical yield )x 100%

An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients

Reaction

Fe₂O₃+3CO⇒2Fe+3CO₂

MW Fe₂O₃ : 159.69 g/mol

mol Fe₂O₃

$\tt \dfrac{100}{159,69}=0.626$

mol Fe₂O₃ : mol Fe = 1 : 2

mol Fe :

$\tt \dfrac{2}{1}\times 0.626=1.252$

mass of Fe(Ar=55.845 g/mol) :

$\tt 1.252\times 55.845=69.92~g$

actual yield = 65 g

theoretical yield = 69.92 g

percent yield :

$\tt =\dfrac{65}{69.92}=0.93=93\%$

8 0

2 years ago

What is the Noble Gas Configuration for Europium?

12345 [234]

Is this a real question? It’s B

6 0

3 years ago

The mass of a proton is approximately equal to

Marrrta [24]

The correct answer is option 1. The mass of a proton is approximately equal to 1 atomic mass unit. They almost have the same mass with a<span> neutron </span>while the electron is about 2000 times lighter than the two. The three mentioned particles are the subatomic particles found in an atom.

3 0

3 years ago