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3 years ago

PLEASE HELP!!

Chemistry

2 answers:

Maurinko [17]3 years ago

4 0

Answer: b

Explanation:

lana66690 [7]3 years ago

3 0

Answer:

Explanation:

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oksano4ka [1.4K]

There are two kinds of mixtures

a) homogeneous : the boundary of the two components is not physically distinct

b) heterogeneous:the boundary of the two components is physically distinct

the following separation techniques are common for mixtures

1) filtration: if the two components are forming heterogeneous mixture we can separate them by filtration.

2) boiling: if boiling point of one of the components is less than other

3) magnetic separation: if one of the component is magnetic

4)sieve method: for solid components with difference in size of particles

5) hand picking

Thus the correct match will be as shown in the figure

3 0

3 years ago

What volume (in L) of a 1.25 M

sleet_krkn [62]

Answer:

V1= 0.305L

Explanation:

To find the initial volume of 1.25M potassium fluoride needed to make tge dilution specified in the question, we can use: C1 × V1 = C2 × V2

Since the question wants the volume in litres, convert 455 mL to L

455/ 1000

= 0.455 L

Now make the substitution

1.25 × V1 = 0.838 × 0.455

Rearrange to make V1 the subject

V1=

$\frac{0.838 \times 0.455}{1.25 } = 0.305$

4 0

3 years ago

How much energy is released by the decay of 3 grams of 230Th in the following reaction 230 Th - 226Ra + "He (230 Th = 229.9837 g

Serhud [2]

Answer: The energy released for the decay of 3 grams of 230-Thorium is $2.728\times 10^{-15}J$

Explanation:

First we have to calculate the mass defect $(\Delta m)$ .

The equation for the alpha decay of thorium nucleus follows:

$_{90}^{230}\textrm{Th}\rightarrow _{88}^{226}\textrm{Ra}+_2^{4}\textrm{He}$

To calculate the mass defect, we use the equation:

Mass defect = Sum of mass of product - Sum of mass of reactant

$\Delta m=(m_{Ra}+m_{He})-(m_{Th})$

$\Delta m=(225.9771+4.008)-(229.9837)=1.4\times 10^{-3}amu=2.324\times 10^{-30}kg$

(Conversion factor: $1amu=1.66\times 10^{-27}kg$ )

To calculate the energy released, we use Einstein equation, which is:

$E=\Delta mc^2$

$E=(2.324\times 10^{-30}kg)\times (3\times 10^8m/s)^2$

$E=2.0916\times 10^{-13}J$

The energy released for 230 grams of decay of thorium is $2.0916\times 10^{-13}J$

We need to calculate the energy released for the decay of 3 grams of thorium. By applying unitary method, we get:

As, 230 grams of Th release energy of = $2.0916\times 10^{-13}J$

Then, 3 grams of Th will release energy of = $\frac{2.0916\times 10^{-13}}{230}\times 3=2.728\times 10^{-15}J$

Hence, the energy released for the decay of 3 grams of 230-Thorium is $2.728\times 10^{-15}J$

5 0

3 years ago

Which is a single ringed nitrogeo base? A)adenine B)guanine C)thymine D)ribose

pogonyaev

A single ringed nitrogeo base is thymine (C)

3 0

3 years ago

How does electronegativity impact polarity of molecules?

marysya [2.9K]

Electronegativity is the measure of the ability of an atom to attract electrons to itself. Fluorine is the most electronegative element and francium is one of the leastelectronegative. ... The molecule's polarity will be determined on the negative and positive regions on the outer atoms in the molecule.

6 0

3 years ago