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3 years ago

Pls help! its 20pts! brainliest, rattings, thanks, etc...

Chemistry

2 answers:

s344n2d4d5 [400]3 years ago

6 0

4: A - CO2

5: D- Magnesium chloride

6: A- Electrons are shared in a covalent bond

7: C- 12

I hope this helped :)

Brainliest?

Misha Larkins [42]3 years ago

5 0

Question 4: The first one

Question 5: The fourth one

Question 6: The first one

Question 7: The third one

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After gathering sufficient evidence to generate an _____for a nutrient, that value is used to establish an RDA for the same nutr

nlexa [21]

Answer:

Estimated Average Requirement (EAR).

Explanation:

Hello,

In this case, it is important to consider that Dietary Reference Intakes (DRIs) are reference values to quantitatively estimate the nutrient necessities to be taken for planning and assessing diets for healthy people. On the other hand, the Recommended Dietary Allowance (RDA) is the average daily dietary intake level that is enough to know the nutrient necessity of nearly all (about 98%) healthy individuals in a particular population. The answer is Estimated Average Requirement (EAR) which is a nutrient intake value that is considered to meet the necessity of half (50%) the healthy individuals in a particular population.

Best regards.

6 0

3 years ago

silver has an atomic mass of 107.868 amu. silver has two common isotopes. one of the isotopes has a mass of 106.906 amu and a re

Sunny_sXe [5.5K]

A. The abundance of the 2nd isotope is 48.119%

B. The mass of the 2nd isotope is 108.905 amu

Let the 1st isotope be A

Let the 2nd isotope be B

A. Determination of the abundance of the 2nd isotope

Abundance of isotope A = 51.881%.

<h3>Abundance of isotope B =? </h3>

Abundance of B = 100 – A

Abundance of B = 100 – 51.881

<h3>Abundance of B = 48.119%</h3>

B. Determination of the mass of the 2nd isotope

Atomic mass of silver = 107.868 amu.

Mass of 1st isotope (A) = 106.906 amu

Abundance of isotope A (A%) = 51.881%.

Abundance of isotope B (B%) = 48.119%

<h3>Mass of 2nd isotope (B) =? </h3>

$atomic \: mass = \frac{mass \: of \:A \times \:A\%}{100} + \frac{mass \: of \:B \times \:B\%}{100} \\ \\ 107.868 = \frac{106.906\times \ \: 51.881}{100} + \frac{mass \: of \:B \times \:48.119}{100} \\ \\ 107.868 = \: 55.464 + 0.48119 \times mass \: of \:B \\ \\ collect \: like \: terms \\ \\ 0.48119 \times mass \: of \:B = 107.868 - 55.464 \\ \\ divide \: both \: side \: by \: 0.48119 \\ \\ mass \: of \:B = \frac{107.868 - 55.464 }{0.48119} \\ \\ mass \: of \:B =108.905 \: amu \\ \\$

Therefore, the mass of the 2nd isotope is 108.905 amu

Learn more: brainly.com/question/7955048

6 0

2 years ago

Please help... will give brainiest

Dvinal [7]

Answer:

The answer will be ：

In year 1869

Russian scientist named Dmitri Mendeleev

Chart called Mendeeleves periodic table

increasing atomic masses

physical and chemical properties.

Hope this Helps

Best of luck ！！

7 0

3 years ago

Need help ASAP!! What is a function mitochondrion

NISA [10]

Answer:

powerhouse of the cell

Explanation:

Mitochondria produce ATP, a necessary sugar that runs the cell

3 0

3 years ago

An unknown amount of mercury (II) oxide was decomposed in the lab. Mercury metal was formed and 5.20 L of oxygen was released at

Yakvenalex [24]

Answer:

<u>68.3g</u>

Explanation:

<u>1. Word equation:</u>

<em>mercury(II) oxide → mercury + oxygen </em>

<u>2. Balanced molecular equation:</u>

2HgO → 2Hg + O₂(g)

<u>3. Mole ratio</u>

Write the ratio of the coefficients of the substances that are object of the problem:

$2molHgO/1molO_2$

<u>4. Calculate the number of moles of O₂(g)</u>

Use the equation for ideal gases:

$pV=nRT\\\\\\n=\dfrac{pV}{RT}\\\\\\n=\dfrac{0.970atm\times5.20L}{0.08206atm.L/K.mol\times 390.0K}\\\\\\n=0.1576mol$

<u>5. Calculate the number of moles of HgO</u>

$\dfrac{2molHgO}{1molO_2}\times 0.1576molO_2=0.315molHgO$

<u>6. Convert to mass</u>

mass = # moles × molar mass

molar mass of HgO: 216.591g/mol

mass = 0.315mol × 216.591g/mol = 68.3g

7 0

3 years ago