Question 1 (1 point)

Chemistry

1 answer:

Colt1911 [192]2 years ago

8 0

Answer:

Both are made up of two substances that are not chemically combined.
oxygen (O2)
carbon dioxide (CO2 )
air (N2 mixed with O2 and CO2)
Pure substances cannot be separated by physical means.

Explanation:

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7. Use the concepts of relative abundance and relative weight to explain why carbon has an atomic mass of 12.011 amu when there

Dvinal [7]

The uncertainties of the delta measurements and the uncertainty of the atomic weight derivedfrom the best measurement of isotopic abundances constrain the number of significant figures in theatomic-weight values of the upper and lower bounds. For carbon, the fifth digit after the decimal pointis uncertain because of the uncertainty value of 0.000 027. Therefore, the number of significant digitsin the atomic-weight value is reduced to four figures after the decimal point. The Commission may rec-ommend additional conservatism and reduce the number of significant figures further. For the lowerbound of carbon, 12.009 635 is truncated to 12.0096. For an upper bound, the trailing digit is increasedto ensure the atomic-weight interval encompasses the atomic-weight values of all normal materials. Inthe case of carbon, the upper bound is adjusted from 12.011 532 to 12.0116 to express four digits afterthe decimal point. The lower and upper bounds are evaluated so that the number of significant digits ineach is identical. If a value ends with a zero, it may need to be included in the value to express therequired number of digits. The following are examples of lower and upper atomic-weight bounds foroxygen that could be published by the Commission in its various tables.

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Extracted from" Atomic weights of the elements 2009 (IUPAC Technical Report)"

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2 years ago

By which mechanism would a steroid molecule diffuse into the cell?

LUCKY_DIMON [66]

Answer: Directly through the phospholipid membrane

Explanation:

The cell membrane consist of a phospholipid bilayers structure. In the interior of the membrane, the phospholipid tail are hydrophobic, which makes the cell membrane to be selectively permeable, it is permeable to non polar molecules and impermeable to polar molecules.

Because Steroids are fat soluble, non polar compounds, they can diffuse directly through the hydrophobic, non polar core of the phospholipid bilayer without the use of carrier proteins.

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3 years ago

The chemical equation below shows the decomposition of nitrogen triiodide (NI3) into nitrogen (N2) and iodine (I2). 2NI3 Right a

yuradex [85]

The moles of I₂ will form from the decomposition of 3.58g of NI₃ is 0.0136 moles.

<h3>How we calculate moles?</h3>

Moles of any substance will be calculated as:

n = W/M, where

W = required mass

M = molar mass

Given chemical reaction is:

2NI₃ → N₂ + 3I₂