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3 years ago

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Mass and energy are conserved Question 13 options: A) only in chemical changes. B) always in physical changes and sometimes in c

hemical changes. C) only in physical changes. D) in chemical changes and physical changes.

1 answer:

Roman55 [17]3 years ago

3 0

Answer:

B

Explanation:

sometimes it can change chemically but not all the time.

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The solubility of N2 in blood at 37°C and a partial pressure of 0.80 atm is 5.6 ✕ 10−4 mol·L−1. A deep-sea diver breathes compre

marysya [2.9K]

Answer:

0.0126 moles are released

Explanation:

Using Henry's law, where the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid:

S = k×P

<em>Where S is solubility (5.6x10⁻⁴molL⁻¹), k is Henry's constant and P is partial pressure (0.80atm)</em>

Replacing:

<em>5.6x10⁻⁴molL⁻¹ / 0.80atm = 7x10⁻⁴molL⁻¹atm⁻¹</em>

Thus, with Henry's constant, solubility of N₂ when partial pressure is 3.8atm is:

S = 7x10⁻⁴molL⁻¹atm⁻¹ × 3.8atm

S = 2.66x10⁻³molL⁻¹

Thus, when the deepd-sea diver has a pressure of 3.8amt, moles dissolved are:

6.0L × 2.66x10⁻³molL⁻¹ = <em>0.01596 moles of N₂</em>

At the surface, pressure is 0.80atm and solubility is 5.6x10⁻⁴molL⁻¹, moles dissolved are:

6.0L × 5.6x10⁻⁴molL⁻¹ = <em>3.36x10⁻³mol</em>

Thus, released moles are:

0.01596mol - 3.36x10⁻³mol = <em>0.0126 moles are released</em>

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3 years ago

Which of the following electron configurations for neutral atoms is correct?

geniusboy [140]

Argon: 1s22s22p63s23p6 is right answer,

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3 years ago

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Give an element <br><br> it is used as fuel in nuclear reactors

bazaltina [42]

Answer:

Uranium

Explanation:

The only natural element currently used for nuclear fission in reactors is uranium. Natural uranium is a highly energetic substance: one kilogram of it can generate as much energy as 10 tonnes of oil. Naturally occurring uranium comprises, almost entirely, two isotopes: U238 (99.283%) and U235 (0.711%).

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3 years ago

8. Which of the following elements reacts like calcium (Ca) but with less atomic

Salsk061 [2.6K]

Answer:

Magnesium (Mg)

Explanation:

An element with a lower atomic mass than Calcium that has similar chemical property is the element Magnesium (Mg).

This because, elements in the same group or family on the periodic table has similar chemical properties.

Magnesium belongs to the same group as Calcium, other elements are:

Be Mg Ca Sr Ba Ra

The group is made of the alkaline earth metals. They have two valence electrons in their outer shell.

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3 years ago

A) indicate the volume of the liquid and its shape after pouring it into the beaker

Naily [24]

Answer:

a). Volume is 30 cm³ and it has a indefinite shape.

Volume of the liquid is measured using a conical flask on the right.

c). Drinking water is a homogeneous mixture though it is a compound. And it has a indefinite shape though it takes up shape of a container.

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2 years ago