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3 years ago

How many valance electrons does He need to get to 8

Chemistry

1 answer:

mote1985 [20]3 years ago

5 0

Answer:

Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons

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Which element of the periodic table is named after the moon

Troyanec [42]

Answer:

The answer to your question is Selenium

Explanation:

The origin of the names of the elements comes from different origins

For example

Sanskrit words. 14 elements have roots from this language

Planets, 4 elements took their names from the planets.

Greek, 42 elements took their names from these languages

The name of Selenium comes from the greek that means moon.

8 0

3 years ago

How does electromagnetism play a role in space

mr_godi [17]

Answer:

Magnets can be used in space. ... One class of magnets, called electromagnets, does need electricity to work.

Explanation:

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3 years ago

A small piece of hot metal is placed in cooler water. The metal is left in the water

scoundrel [369]

Answer: The amount of energy lost by the metal is equal to the amount of energy gained by the water

Explanation:

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2 years ago

How many moles of sodium hydroxide would react with 1 Mole of sulphuric acid?

Paul [167]

Answer:

Two moles.

Explanation:

Sulphuric (sulfuric) acid $\rm H_2SO_4$ is a diprotic acid. When one mole of $\rm H_2SO_4$ molecules dissolve in water, two moles of $\rm H^{+}$ ions would be produced.

$\rm H_2SO_4 \to 2\, H^{+} + {SO_4}^{2-}$ .

On the other hand, sodium hydroxide $\rm NaOH$ is a monoprotic base. When one mole of $\rm NaOH$ formula units dissolve in water, only one mole of hydroxide ions $\rm OH^{-}$ would be produced.

$\rm NaOH \to Na^{+} + OH^{-}$ .

Note that $\rm H^{+}$ and $\rm OH^{-}$ react at a one-to-one ratio:

$\rm H^{+} + OH^{-} \to H_2O$ .

As a result, it would take $2\; \rm mol$ of $\rm OH^{-}$ to react with the $\rm 2\; mol$ of $\rm H^{+}$ that was released when $1\; \rm mol$ of $\rm H_2SO_4$ is dissolved in water. Since one mole of $\rm NaOH$ formula units could produce only one mole of $\rm OH^{-}$ , it would take $\rm 2\; mol$ of $\rm NaOH$ formula units to produce that $2\; \rm mol$ of $\rm OH^{-}$ for reacting with $1\; \rm mol$ of $\rm H_2SO_4$ .

3 0

3 years ago

A container holds 15.0 g of phosphorous gas at a pressure of 2.0 atm and a temperature of 20.0 Celsius. What is the density of t

erik [133]

<span>Density is a value for mass, such as kg, divided by a value for volume, such as m3. Density is a physical property of a substance that represents the mass of that substance per unit volume. We calculate as follows:

PV = nRT
PV = mRT/ Molar mass
m/V = P(molar mass)/RT
Density = P(molar mass)/RT
Density = 2.0 ( 30.97 ) / 0.08206 ( 20 + 273.15) = 2.57 g/L <----First option</span>

5 0

3 years ago

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