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3 years ago

Explain why elements and compounds are pure substances

2 answers:

8 0

N2 - Element; Pure substance O2 - Element; Pure substance N2O - Compound; Pure Substance Air - Homogeneous; Solution

neonofarm [45]3 years ago

6 0

Elements and compounds are substances because we know exactly what is in them. Elements are only one kind of atom and have a symbol. Compounds have a formula telling us exactly how many of what kind of atom make up that compound

Solutions, homogeneous mixtures, not only contain 2 compounds, but we do not know how much of each. We can make salt water with one grain of salt in a cup of water or a drop of water in a cup of salt. Mixtures do not have a formula because they can be any concentration.

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3. Description of which organelle betul "Creates a physical barrier ;

Ghella [55]

The cell membrane performs those functions. It is the outer layer of a cell and it creates a barrier, regulates material entry and exit, uses chemical signals, and creates structure.

4 0

3 years ago

List the metric ladder from largest to smallest.

-Dominant- [34]

Answer:

Kilo- Hecto- Deka- Unit Deci- Centi- Milli

Explanation:

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3 years ago

A chemist makes of magnesium fluoride working solution by adding distilled water to of a stock solution of magnesium fluoride in

mojhsa [17]

The question is incomplete, here is the complete question:

A chemist makes 600. mL of magnesium fluoride working solution by adding distilled water to 230. mL of a stock solution of 0.00154 mol/L magnesium fluoride in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.

Answer: The concentration of chemist's working solution is $5.90\times 10^{-4}M$

Explanation:

To calculate the molarity of the diluted solution (chemist's working solution), we use the equation:

$M_1V_1=M_2V_2$

where,

$M_1\text{ and }V_1$ are the molarity and volume of the stock magnesium fluoride solution

$M_2\text{ and }V_2$ are the molarity and volume of chemist's magnesium fluoride solution

We are given:

$M_1=0.00154M\\V_1=230mL\\M_2=?M\\V_2=600mL$

Putting values in above equation, we get:

$0.00154\times 230=M_2\times 600\\\\M_2=\frac{0.00154\times 230}{600}=5.90\times 10^{-4}M$

Hence, the concentration of chemist's working solution is $5.90\times 10^{-4}M$

8 0

3 years ago

Which of the following is the best reason to read directions carefully before beginning any type of lab?

salantis [7]

Answer:

Explanation:i think

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3 years ago

Which of the following compounds contains both ionic and covalent bonds? KOH N2O5 CH3OH Na2O

dusya [7]

Answer: a.KOH

Potassium hydroxide is an ionic compound where the K+ is the cation and OH−is the anion. At the same time, the compound also contains a covalent bond since the anion, OH−is formed from electron sharing between the O and H atoms.

Hope this helps........ Stay safe and have a Merry Christmas! :D

Explanation:

4 0

3 years ago