How many valence electrons does a helium atom have?

Chemistry

2 answers:

Setler [38]3 years ago

7 0

Answers are;

1. A (The answer is 2)

2. K+

3. It gains electrons.

4. The attraction of metal ions to mobile electrons

5. A caution and an anion

6. Body-centered cubic

aev [14]3 years ago

4 0

Helium atoms has TWO electrons in valence shell....

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"Two major varieties of igneous rock are _______ and ________. What is the difference between these two types of igneous rock?"

grandymaker [24]

Answer:

Intrusive and Extrusive igneous rocks.

Explanation:

Igneous rocks are defined as those rocks that are formed when magma undergoes the process of crystallization and solidification at or below the earth's surface. For example, Granite, Rhyolite, Gabbro and Diorite.

The igneous rocks are of two different types, namely-

Intrusive igneous rocks- This type of igneous rocks are formed when the magma crystallizes below or within the earth's crust. For example, Granite.

Extrusive igneous rocks- This type of igneous rocks are formed when the magma crystallizes and solidifies at the surface of the earth. For example, Basalt.

8 0

3 years ago

Suppose of copper(II) acetate is dissolved in of a aqueous solution of sodium chromate. Calculate the final molarity of acetate

uranmaximum [27]

Answer:

0.0714 M for the given variables

Explanation:

The question is missing some data, but one of the original questions regarding this problem provides the following data:

Mass of copper(II) acetate: $m_{(AcO)_2Cu} = 0.972 g$

Volume of the sodium chromate solution: $V_{Na_2CrO_4} = 150.0 mL$

Molarity of the sodium chromate solution: $c_{Na_2CrO_4} = 0.0400 M$

Now, when copper(II) acetate reacts with sodium chromate, an insoluble copper(II) chromate is formed:

$(CH_3COO)_2Cu (aq) + Na_2CrO_4 (aq)\rightarrow 2 CH_3COONa (aq) + CuCrO_4 (s)$

Find moles of each reactant. or copper(II) acetate, divide its mass by the molar mass:

$n_{(AcO)_2Cu} = \frac{0.972 g}{181.63 g/mol} = 0.0053515 mol$

Moles of the sodium chromate solution would be found by multiplying its volume by molarity:

$n_{Na_2CrO_4} = 0.0400 M\cdot 0.1500 L = 0.00600 mol$

Find the limiting reactant. Notice that stoichiometry of this reaction is 1 : 1, so we can compare moles directly. Moles of copper(II) acetate are lower than moles of sodium chromate, so copper(II) acetate is our limiting reactant.

Write the net ionic equation for this reaction:

$Cu^{2+} (aq) + CrO_4^{2-} (aq)\rightarrow CuCrO_4 (s)$