Answer:
The compounds in the samples will leach into the pool of developing solvent resulting in poor resolution.
Explanation:
The aim of thin layer chromatography is the separation of a mixture. Usually, the stationary phase is spotted with the mixture. A mark is made with a pencil at the point to be spotted.
It is necessary to note that the solvent must be below the spot where the mixture is. This is because, if the solvent is above the spot of the mixture to be separated, the components of the mixture will dissolve away in the solvent resolution in poor separation. This is exactly what will happen when the sample is spotted at 1.0 cm above the bottom when the solvent is 1.2 cm above the bottom.
The rows in the periodic table are called periods.
What is true about elements in the same period?
Answer:
elements in the same period have the same number of shells
the period number the element is in, that is the number of shells it has.
How many molecules are in 1.35 mol of CS2
Answer:
There are there are 8.13-10^25
Explanation:
N(CS2)= 1.35* (times) 6.02-10^ 25= 3.13-10^25 molecules
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.12×10²³ molecules are in 1.35 mole of CS[tex]_2[/tex].
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.
we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number
number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)
number of moles of CS[tex]_2[/tex] = 1.35 mol
Substituting all the given values in the above equation, we get
number of atoms/molecules= 1.35 × 6.022×10²³
number of atoms/molecules=8.12×10²³ molecules
Therefore, 8.12×10²³ molecules are in 1.35 mole of CS[tex]_2[/tex].
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please anyone help me with this
Answer:
matter is anything that takes up space while elements are subtanxes that can be broken down
what is chemistry about
Answer:
Explanation:
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything.
Answer:
its the science that deals with the properties, composition, and structure of substances like elements and compounds, the transformations they undergo, and the energy that is released or absorbed during these processes
- include the process that causes the sun to release so much energy
-The equation for the process that causes the energy. -show what is happening to all the energy coming from the sun.
-how does it affect earth and life on earth
Answer: nuclear fusion, equation:(Z + N) in a nucleus of mass M. The formula is B = (Zmp + Nmn − M)c2, All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.
Explanation: i explained everything in the answer hope this helped
which element has an atom with the following composition? 24 protons, 28 neutrons and 24 electrons.
hello~i will really appreciate it if you answer all this♡
☆
1.How many valence electrons do noble gases like Ne,Ar and Kr have?
a.1.
b.2
c.6
d.7
2.The following describe ionic bonding,EXCEPT____.
a.It involves the transfer of electrons.
b.It involves sharing of electrons.
c.atoms either gain or lose electrons.
d.It is a bond between a metal and a non-metal.
3.Which of the following pairs of atoms is most likely to form a covalent compound?
a.C,O
b.Na,O
c.Mg,Br
d.Ba,CI
4.Which of the following is a metal?
a.O
b.S
c.K
d.C
5.Which is not a type of a chemical bonding?
a. Polar bonding
b.Metallic bonding
c.ionic bonding
d.covalent
||. A. Use Lewis structures to show . the transfer of electrons in the given combinations.
1.K +Br
2.Ba + I
3.Be + O
4.Na + S
5.AI + F
B.What ionic charge will the following elements have?PLEASE JUSTIFY YOUR ANSWER.
1. Group 2A
2. Group 5A
3.Group 6A
C.Predict whether the bonding in the oxides of the following elements is covalent or ionic.EXPLAIN YOUR ANSWER.
1.Aluminum
2.Magnesium
3.Phosphorus
4.silicon
5.sodium
|||. Write the electron configuration of the following elements.
1. Ti
2. V
3. Se
4. Ag
5. Zr
thank you!
to your hardwork★
Explanation:
1)Noble gases have stable valence electron of 2 and 8.
2)B- ionic compounds do not require sharing of electron.
3)B- sodium and oxygen will likely form a covalent compound.
4) C- potassium
5) A- polar bonding
6)
which 2 statements describe a mixture?
1. It includes atoms of different elements.
2. Its parts can be separated using physical means.
3. It can result from chemical bonding.
4. It is a pure substance.
Answer:
It's parts can be separated using physical means.It is a pure substance.If a sample of copper is 215g, how many moles of copper atoms are in the sample?
Answer:
3.38 moles.
Explanation:
The following data were obtained from the question:
Mass of copper (Cu) = 215 g
Number of mole of copper (Cu) =...?
The number of mole of copper (Cu) in 215 g can be obtained as follow:
Mass of copper (Cu) = 215 g
Molar mass of copper (Cu) = 63.55 g/mol
Number of mole of copper (Cu) =...?
Mole = mass /Molar mass
Mole of Cu = 215/63.55
Mole of Cu = 3.38 moles
Therefore, 3.38 moles of copper (Cu) is present in the sample.
What do you think is the difference between an "open" system & a "closed" system?
Answer:
Hope it help you
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Plz mark my answer brainliest✍️✍️
Explanation:
There are three types of systems in thermodynamics: open, closed, and isolated. An open system can exchange both energy and matter with its surroundings. ... A closed system, on the other hand, can exchange only energy with its surroundings, not matter.
REAL NAME - SHRESTH DUBEY
state two advantages of parallel over series connection in table form?
Advantages of parallel combination over series combination are:
1) In parallel combination each appliance gets the full voltage.
2) If one appliance is switched on/of others are not affected.
3) The parallel circuit divide the current through the appliances. Each appliance gets proper current depending on its resistance.
4) In a parallel combination it is very easy to connect or disconnect a new appliance without affecting the working of other appliances.
choose what you like!
Note that there are also some disadvantages to using parallel connections over series connections, such as increased complexity in wiring and the need for additional safety measures when working with high voltage circuits. The choice between series and parallel connections depends on the specific requirements of the circuit and the devices being used.
Metamorphic means “________________.”
A}to turn into rock
B]to make into minerals
C]to change form
D]to press down
In Greek metamorphic means 'to change form ' . Hence the answer to this question will be ;
C) To change form
If a boulder sits at rest on top of a mountain what conclusion can be made about the forces acting on the
A boulder sits at rest on top of a mountain. What conclusion can be made about the forces acting on the boulder? The forces acting on the boulder are balanced (net force equals zero).
If a boulder sits at rest on the top of the mountain , the forces acting on the boulder are zero as it is in the state of rest.
What is a force?
Force is defined as a cause which is capable of changing the motion of an object. It can cause an object which has mass to change it's velocity. It is also simply a push or a pull . It has both magnitude as well as direction.Hence, it is a vector quantity.
It has SI units of Newton and is represented by'F'.Newton's second law states that force which acts on an object is equal to momentum which changes with time. If mass of object is constant, acceleration is directly proportional to net force acting on an object.
The concepts which related to force are thrust and torque .Thrust increases the velocity of an object and torque produces change in rotational speed of an object.
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Can anyone explain to me how I solve 3x10^8 / 3.82x10^-7
I know the answer due to referring to the key but I'm not sure how they got it. Answer was 7.85x10^14
Answer:
You have to do this on a calculator. So when you put it in the calculator you will get 7.85x10^14.
3x10^8 is the speed of light. 3.82x10^-7 is the number in the question.
You can solve it like this
3x10^8
------------------
3.82x10^7
But you would do this on a calculator.
5. What is a hypothesis and how is it used?
Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
A hypothesis is used in an experiment to define the relationship between two variables. The purpose of a hypothesis is to find the answer to a question. A formalized hypothesis will force us to think about what results we should look for in an experiment. The first variable is called the independent variable
i hopes this helps :)
Calculate the maximum mass of potassium sulfate, K2SO4, that could be formed when 4.9 g of sulfuric acid reacts with excess potassium hydroxide.
H2SO4 + 2KOH → K2SO4 + 2H2O
Answer:
From 4.9 g of sulfuric acid 8.175 g of potassium sulfate is formed.
Explanation:
Given data:
Mass of H₂SO₄ = 4.9 g
Mass of K₂SO₄ formed = ?
Solution:
Chemical reaction:
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O
Number of moles of H₂SO₄:
Number of moles = mass/ molar mass
Number of moles = 4.9 g/ 98.1 g/mol
Number of moles = 0.05 mol
Now we will compare the moles of H₂SO₄ with K₂SO₄ .
H₂SO₄ : K₂SO₄
1 : 1
0.05 : 0.05
Mass of K₂SO₄:
Mass = number of moles × molar mass
Mass = 0.05 mol × 174.3 g/mol
Mass = 8.715 g
Thus, from 4.9 g of sulfuric acid 8.175 g of potassium sulfate is formed.
Which statement best describes how entrepreneurship affects a society's
economy?
A. It encourages people to take risks to create new products.
B. It organizes the people who help a business operate.
C. It provides the raw materials needed to produce goods.
D. It supplies businesses with the tools they need to function.
Answer:it’s a
Explanation:cause
a screwdriver has a volume of 0.418 cubic centimeters. it also has the mass of 2.3 grams. what is the screwdrivers density
Answer:
The answer is 5.50 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{2.3}{0.418} \\ = 5.50239234...[/tex]
We have the final answer as
5.50 g/cm³Hope this helps you
Answer:
Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun.
Explanation:
Which substances from the simulation are more alkaline than water?
Which
Answer:
The substances more alkaline than water are;
1) Spit, 2) Blood, 3) Hand Soap, and 4) Drain Cleaner
Explanation:
The diagram in the simulation displays a list of liquid substances, arranged from bottom to top in the order of increasing alkalinity.
The ph of water is 7.0
The ph of spit (saliva) is between 6.2 and 7.6
The ph of blood is about 7.4
The ph of hand soap is between 9 and 10
The ph of drain cleaner is between 12 and 14.
who Organized elements into four groups based on propertie
anwser this ASAP please
Answer:
Its D :)
Or not i haven't done this in a while-
6. In our modern times, the atom can be subdivided into
A.) protons and electrons, only
B.) protons and neutrons, only
C.) protons, neutrons, and electrons, only
D.) neutrons and electrons, only
Answer:
C.) protons, neutrons, and electrons, only
Explanation:
According to the modern atomic theory, we can distinguish 2 parts in an atom:
The nucleus, where is the majority of the mass of the atom, that is, protons and neutronsThe external shell, where are the electrons.In a neutral atom, there are the same number of protons (positive charges) as electrons (negative charges).
Which of the following is not a gas in the Earth's atmosphere? A. oxygen B. carbon dioxide C. sulfur D.nitrogen 1
Which iron pot has the least thermal energy?
A. A5 kg pot at 130°C
B. A 2 kg pot at 120°C
C. A 5kg pot at 25°C
D. A 2 kg pot at 25°C
Answer: D. A 2 kg pot at 25C.
Explanation:
19. Chemical properties can be used to
(1) differentiate between two compounds
(2) determine the temperature of a substance
(3) determine the density of a substance
(4) differentiate between two neutrons
Answer:differentiate between two compounds i think!
Explanation: taking a test!
Answer:(1) differentiate between two compounds
Explanation:
A Chemical property tells us the characteristics of a particular matter or substance after a chemical change. This property helps us to differentiate a compound from another or differentiate elements or substances. Examples of a Chemical property are acidity, reactivity and heat, etc .
For example to differentiate between Water H2O and Hydrogen peroxide, H202
Even though they are made up of oxygen and hydrogen. Hydrogen peroxide (H2O2), has more(1) oxygen than water (H2O).
Using Acidity as a chemical property to differentiate these substances
Water, H20 is amphoteric in nature ie having both acidic and basic properties, while H202 is a weak acid.
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Examples of physical change include?
A. Melting
B. Boiling
C. Freezing
D. All of these are examples of physical change
Answer:
All of these examples are physical changes.
Explanation:
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition.
Help fast I have a few left
Answer: A
Explanation: 0.00624 x 10^8
All you have to do is move the . 8 units left
This gives you 624000.0
can you guys help me please? I dont get what im supposed to do here.
True or false igneous rocks can only turn into metamorphic
Answer:
this is false igneous rocks can turn into either sedimentary rocks and they can be metamorphic
Explanation:
i hope this helps your welcome :)
Answer:
False
Explanation:
Igneous rocks can turn into sedimentary rocks as well as metamorphic.
Urgent please help!!
Which of these is a chemical property of a substance?
A) texture
B) ductility
C) reactivity
D) conductivity
Answer:
reactivity
Explanation: