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Andru [333]
3 years ago
7

A scientific theory is _____.What have chemists done to help people conserve energy?

Chemistry
1 answer:
Lena [83]3 years ago
5 0

Answer:

the have done so many things to help

You might be interested in
3. Classify the following plants along with two main characteristics: al Cycus b) Bamboo c) Lemna d) Paddy a) Sugarcane f) Pinus
madreJ [45]

Answer:

A. cycas

1. it is thick and scaly

2. it grow relatively slowly and have a large, terminal rosette of leaves.

B. bamboo

1. it is very durable

2. it is both flexible and elastic

C. lemna

1. it grows as simple free-floating thalli on or just beneath the water surface

2. it are small, not exceeding 5 mm in length

D. paddy

1. it is variety purity

2. it degree of purity

E. sugarcane

1. it is bear long sword-shaped leaves

2. it's stalks are composed of many segments, and in each joint there is a bud

4 0
2 years ago
What is the symbiotic relationship of bighorn sheep and worms
Dmitry_Shevchenko [17]

Answer:

Lungworms live in the lungs of bighorn sheep causing them to be sick, or even die.

Explanation:

hope this helps

pls mark me brainliest

5 0
3 years ago
2A1 (s) + 3C12 (g) --> 2AlCl3 (s) (balanced)
Dennis_Churaev [7]

Answer:

32.3%

Explanation:

Percent yield is defined as:

Actual yield (125.5g) / Theoretical Yield * 100

To find theoretical yield we have to find the moles of aluminium. As 2 moles of Al produce 2 moles of AlCl3, the moles of Al = Moles AlCl3.

With these moles we can find the mass assuming a 100% of yield (Theoretical Yield) as follows:

<em>Moles Al = Moles AlCl3 (Molar mass Al = 26.98g/mol)</em>

72g Al * (1mol / 26.98g) = 2.67 moles AlCl3

<em>Mass AlCl3 (Molar mass: 133.34g/mol)</em>

2.67 moles AlCl3 * (133.34g / mol) = 355.8g AlCl3

Percent Yield = 125.5g / 355.8g * 100 =

<h3>32.3% </h3>
5 0
3 years ago
Which solution will provide the LOWEST freezing point? Group of answer choices 1.2 M MgCl2 1.60 M KI 1.0 M Na2CO3 1.5 M NaCl
Anettt [7]

Answer:

KI 1.0 M

Explanation:

Freezing point of a substance is a colligative property. This means that it depends on the amount of substance present is the system.

The freezing point is given by; T - Ta = K * m * i

Where;

T = freezing point of the pure solution

Ta = freezing point of the solution containing the solute

K = freezing point constant

m = molality of the solution

i= Van't Hoff factor

If we look at all the options provided, KI has only two particles in solution and a molality of 1.0 m hence it should exhibit the lowest freezing point of solution.

8 0
3 years ago
Calculate the wavelength for the transition from n = 4 to n = 2, and state the name given to the spectroscopic series to which t
finlep [7]

Answer:

The wavelength for the transition from n = 4 to n = 2 is<u> 486nm</u> and the name  name given to the spectroscopic series belongs to <u>The Balmer series.</u>

Explanation

lets calculate -

Rydberg equation-   \frac{1}{\pi } =R(\frac{1}{n_1^2} -\frac{1}{n_2^2})

where ,\pi is wavelength , R is Rydberg constant ( 1.097\times10^7), n_1 and n_2are the quantum numbers of the energy levels. (where n_1=2 , n_2=4)

Now putting the given values in the equation,

                \frac{1}{\pi }=1.097\times10^7\times(\frac{1}{2^2} -\frac{1}{4^2} )=2056875m^-^1

    Wavelength \pi =\frac{1}{2056875}

             =4.86\times10^-^7 = 486nm

<u>    Therefore , the wavelength is 486nm and it belongs to The Balmer series.</u>

8 0
3 years ago
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