Na₂O is an ionic compound. Na is in group 1 which means it has one electron in the outer shell. O is in group 6 so it has 6 electrons in the outer shell.
To become stable atoms need to either lose the electrons in the outer shell or gain electrons to gain a complete outer shell configuration.
To become stable Na loses its outer electron and becomes positively charged. It only loses one electron, so net charge is +1. O to become stable gains 2 electrons to complete its outer shell and becomes negatively charged. since it gains 2 electrons, the net charge is -2.
cation - Na⁺
anion - O²⁻
O gains 2 electrons but Na can give only one electron, therefore 2 Na⁺ ions are required.
the compound can be written by exchanging the charges
ions Na⁺ O²⁻
charge +1 -2
exchange Na₂O
Correct answer is <span>Na has +1 charge and O has -2 charge</span>
Answer:
The answer to your question is Cu(NO₃)₂
Explanation:
To write the chemical formula of a molecule:
1.- Look for the symbols of the elements
Copper = Cu has an oxidation number of +2.
Nitrate = NO₃⁻¹ nitrate is a polyatomic ion so it is composed of nitrogen,
oxygen and its oxidation number is -1.
2.- Write the chemical formula and interchange the oxidation numbers.
Cu⁺² + NO₃⁻¹ ⇒ Cu(NO₃)₂
Find moles:
<span>36.0 g of glucose divided by 180 g/mol = 0.200 moles of glucose </span>
<span>find molarity: </span>
<span>0.200 moles of glucose / 2 litres = 0.100 Molar solution </span>
Answer:
0.5 g/mL----- float
1.0 g/mL---- float
2.0 g/mL-----sink
Explanation:
Those objects will float whose density is less or equal to water density due to lower mass while those object will sink whose density is greater than water because the mass of the object is greater than water. So the density of the object i. e. 0.5 g/mL and 1.0 g/mL will float in the liquid because its density is lower than water which is 1 g/mL while the density of an object i. e. 2.0 g/mL is denser than water so it will sink.
Answer:
- second choice:<em><u> 1.0 g of the solution contains 15 × 10⁻⁶ g of benzene.</u></em>
Explanation:
ppm is a unit of concentration that means parts per million. In grams that is grams of solute per one million (10⁶) grams of solution.
Then, <em>15 ppm of benzene</em> means that there are 15 grams of benzen in 1,000,000 grams of solution.
That leads to:
- 1,000,000 g solution / 15 g benzene
Multiplying numerator and denominator by 10⁻⁶ you find:
- 1,000,000 × 10⁻⁶ g solution / (15 × 10⁻⁶ g benzene)
Simplifying:
- 1.0 g solution / (15 × 10⁻⁶ g benzene)
Which is read as 1.0 g of the solution contains 15 × 10⁻⁶ g of benzene, i.e. the second answer choice.
