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JulsSmile [24]
3 years ago
13

Why must the line of origin be drawn in pencil instead of pen on the chromatography strip?

Chemistry
1 answer:
Kruka [31]3 years ago
5 0

Answer:

Because if you use pen, your chromatography will separate also the colors of the pen and not just your sample.

Explanation:

The pencil since is carbon as simple element, is solid and is not dissolved in solvents like commonly are used in paper chromatography, it will not interrupt the separation of the compounds in your mixture, otherwise, your results will be confuse because you are not sure if the spots that you observe is due to the ink pen or due to the mixture that you want to separate.

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Which waves can travel through empty space?
bagirrra123 [75]

Answer:

light waves a

Explanation:

because there's all kinds of different light in space if you think about it like the bright stars or the bright moon it's kind of like light it just makes sense when it's traveling for space water waves obviously it's not possible that travels through the air or like on a beach sound waves you can't really cure much in space and mechanical waves is pretty much the action of an object or something like that kind of it's pretty much happens on Earth but light waves happen for like asteroids or shooting stars a comments it happens all the time for space so it makes just perfect sense

3 0
2 years ago
Read 2 more answers
What are the 6 things needed on a graph?
Furkat [3]
1. Always give your graph a title in the following form: "The dependence of (your dependent variable) on (your independent variable). <span><span>Let's say that you're doing a graph where you're studying the effect of temperature on the speed of a reaction. In this reaction, you're changing the temperature to known values, so the temperature is your independent variable. Because you don't know the speed of the reaction and speed depends on the temperature, the speed of the reaction is your dependent variable. As a result, the title of your graph will be "The dependence of reaction rate on temperature", or something like that.</span> 

 </span>2. The x-axis of a graph is always your independent variable and the y-axis is the dependent variable.<span>For the graph described above, temperature would be on the x-axis (the one on the bottom of the graph), and the reaction rate would be on the y-axis (the one on the side of the graph) 

 </span>3. Always label the x and y axes and give units.<span>Putting numbers on the x and y-axes is something that everybody always remembers to do (after all, how could you graph without showing the numbers?). However, people frequently forget to put a label on the axis that describes what those numbers are, and even more frequently forget to say what those units are. For example, if you're going to do a chart which uses temperature as the independent variable, you should write the word "temperature (degrees Celsius)" on that axis so people know what those numbers stand for. Otherwise, people won't know that you're talking about temperature, and even if they do, they might think you're talking about degrees Fahrenheit. 
 
</span>4. Always make a line graph<span><span>Never, ever make a bar graph when doing science stuff. Bar graphs are good for subjects where you're trying to break down a topic (such as gross national product) into it's parts. When you're doing graphs in science, line graphs are way more handy, because they tell you how one thing changes under the influence of some other variable. </span> 
 
</span><span>5. Never, EVER, connect the dots on your graph!Hey, if you're working with your little sister on one of those placemats at Denny's, you can connect the dots. When you're working in science, you never, ever connect the dots on a graph.Why? When you do an experiment, you always screw something up. Yeah, you. It's probably not a big mistake, and is frequently not something you have a lot of control over. However, when you do an experiment, many little things go wrong, and these little things add up. As a result, experimental data never makes a nice straight line. Instead, it makes a bunch of dots which kind of wiggle around a graph. This is normal, and will not affect your grade unless your teacher is a Nobel prize winner. However, you can't just pretend that your data is perfect, because it's not. Whenever you have the dots moving around a lot, we say that the data is noisy, because the thing you're looking for has a little bit of interference caused by normal experimental error.</span><span>To show that you're a clever young scientist, your best bet is to show that you KNOW your data is sometimes lousy. You do this by making a line (or curve) which seems to follow the data as well as possible, without actually connecting the dots. Doing this shows the trend that the data suggests, without depending too much on the noise. As long as your line (or curve) does a pretty good job of following the data, you should be A-OK. 

 </span>6. Make sure your data is graphed as large as possible in the space you've been given.<span><span>Let's face it, you don't like looking at little tiny graphs. Your teacher doesn't either. If you make large graphs, you'll find it's easier to see what you're doing, and your teacher will be lots happier.</span> 
 </span><span>So, those are the steps you need to follow if you're going to make a good graph in your chemistry class. I've included a couple of examples of good and bad graphs below so you know what these things are supposed to look like.</span>
5 0
3 years ago
Read 2 more answers
Which statements are true of the reaction below? 2na(s) + cl2(g) 2nacl(s) Check all that apply. A - NaCl is a product B - Na(s)
Bumek [7]

Answer:

A - NaCl is a product

D - Cl2 is a gas

Explanation:

Based on the chemical reaction;

2Na(s) + Cl2(g) → 2NaCl2

  • Sodium metal reacts with chlorine gas to form sodium chloride. Sodium is in solid state, chlorine is in gaseous state and Sodium chloride is in solid state.
  • In the chemical reaction, sodium and chlorine are reactants while sodium chloride is the product.
  • Additionally the chemical reaction above is balanced so as to obey the law of conservation of mass.
4 0
3 years ago
A sample of water contains 5.24x10^22 molecules. How many moles are in this sample?
Helga [31]

Answer:

0.087 moles of water

Explanation:

Given data:

Number of molecules of water = 5.24×10²² molecules

Number of moles of water = ?

Solution:

The given problem will solve by using Avogadro number.

1 mole = 6.022 × 10²³ molecules of water

5.24×10²² molecules × 1 mol / 6.022 × 10²³ molecules

0.87×10⁻¹ mol

0.087 mol

Avogadro number:

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

8 0
3 years ago
Select the correct answer from each drop-down menu.
nataly862011 [7]

The arrow shows that the bond between the chlorine atom and the fluorine atom is nonpolar. The electrons in the bond are pulled more strongly by the fluorine atom, and the chlorine atom is slightly positive.

Explanation:

  • The bond between Chlorine and fluorine is nonpolar bonding because both of them are sharing an equal number of electrons in the bond. H2, F2, and CL2 are common examples of this.
  • Chlorine and fluorine are electronegative molecules but Fluorine is above chlorine in the periodic table. Since fluorine is above Chlorine, fluorine has slightly highest electronegative nature compare to fluorine. This is the reason why Fluorine molecules are attracting electrons more than chlorine atoms. This making chlorine atoms slightly positive in Cl and F bonding.

8 0
3 years ago
Read 2 more answers
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