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.
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.
See related question here: https://brainly.com/question/19594290
Each of the atoms in alkali earths metal Family( group 2) has ___ valence Electrons .
Pleasee help I’ll mark you as brainlister
Fill in the blank
Answer:
the answer is 2 valence electrons
i need help and it’s for science cause i have a bad grade in it and have 3 days to get all my grades up so help pls?
What measuring tool is used to find the volume of a shoe box?
A.water displacement
B.scale
C.beaker
D.ruler
Answer:
D. Ruler
Explanation:
Use the formula to find the volume of a cuboid by measuring the length, width, and height and multiplying all of them by each other.
Reducing child __________, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals.
A.
mortality
B.
maternity
C.
infirmity
D.
infection
Answer: A
Explanation: Mortality means death. And it is a primary goal of Development Goals
Reducing child mortality, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals and the correct option is option A.
What is Mortality?Mortality is defined as the state of the individual being dead. The mortality rate is the death rate of a population which is calculated on the basis of the deaths in the particular region.
Mortality as one of the components of demography is measured as mortality rate.
Mortality meaning provides the basis for mortality rate and its estimation. Mortality is the possibility of and susceptibility to death, and hence, the rate of mortality or the death rate is the measurement of the number of deaths that occur in a particular population, scaled to the size of that population per unit of time.
Therefore, Reducing child mortality, or rate of death, is one of the primary goals of the UN’s Millennium Development Goals and the correct option is option A.
Learn more about Mortality, here:
https://brainly.com/question/6344227
#SPJ3
235/92 U + 1/0 n -> 138/55 Cs + 96/37 Rb + 2 1/0 n
what kind of reaction?
Answer:
Nuclear fission
Explanation:
This reaction is called a nuclear fission reaction. In this reaction, a radioactive decay process occurs in which a heavy nucleus spontaneously disintegrates into two lighter nuclei and several neutrons, with the release of a large amount of energy.
The imbalance between the number of neutrons and protons is responsible for this spontaneous disintegration. Until a stable daughter cell forms, the reaction proceeds.Which term describes this molecular shape?
A. Tetrahedral
B. Bent
C. Trigonal planar
D. Linear
Answer:
A
Explanation:
Tetrahedral
The term that describes the molecular structure is Tetrahedral. The correct option is A.
What is molecular structure?The molecular structure is the structure of the molecular compounds. It tells the presence of ions and bonds in a compound. It is the arrangement of atoms, groups, or ions in a molecule, as well as the quantity and distribution of chemical bonds.
The use and importance of molecular structure are comprehending Nature's complex design principles and blueprints depend on understanding molecular structure.
Perhaps we can start to imitate her lovely items more cheaply and with less negative environmental effects if we can comprehend her plans and fundamental materials. The given compound is tetrahedral.
Thus, the correct option is A. Tetrahedral.
To learn more about molecular structure, refer to the link:
https://brainly.com/question/503958
#SPJ2
Can you tell me the Valence Electron of each element?
Answer:
Lithium oxide.......................
Explanation:
6. magnicium chloride
2.Barium chloride
3. calcium nitride
4. lithium oxide
5. Aluminium sulphide
plzz mark me brainliest
I beg you please please I beg you help me please I’m litterly crying please :(
what are the spectrum lines, and they're color emmited and nanometers
Emission lines are seen as coloured lines on a black background. Absorption lines are seen as black lines on a coloured background. The presence of spectral lines is explained by quantum mechanics in terms of the energy levels of atoms, ions and molecules.
i hope it is helpful:) mark as brainlist
Which type of matter is always made up of only one kind of atom?
A. Element
B. Mixture
C. Molecule
D. Compound
pls answer fast
Answer:
A. element
Explanation:
Answer: Element
Explanation: A substance that is composed of only one type of atom is called an element. At this point, what should amaze you is that all forms of matter in our universe are made with only 118 different building blocks.
Is hydrogen a metal or a nonmetal? How many valence electrons does a hydrogen atom have?
Answer:
hydrogen is a non-metal, and has one valence electron.
Explanation:
Hope this helps!!
Hydrogen shows properties of both metals and nonmetals. However, hydrogen is placed with the alkali metals since it contains one valence electrons.
What is hydrogen ?Hydrogen is the first element in the periodic table. It has only one electron and it is the valence electron of hydrogen. Therefore, hydrogen is placed in the first group of periodic table.
Hydrogen needs one more electrons to become stable. The 17th group elements halogens also have a valency of one. Hence, hydrogen shows some chemical similarities with halogens also.
Mostly hydrogen forms covalent bonds like non-metals and in rare cases, hydrogen forms ionic bonds by donating its electron. Therefore, hydrogen is mostly considered as a non-metal.
Find more on hydrogen;
https://brainly.com/question/11837837
#SPJ2
Rain is falling at 2.00 inches per hour. How many inches have fallen in 6000.0 seconds?
What happens to energy when frequency
is reduced by one half?
Energy is doubled
Energy is squared
Energy is halved
Energy remains constant
Answer:
Energy is halved.
Explanation:
Energy and Frequency are directly proportional. If frequency decreases, energy increases. If frequency increases, energy increases. If frequency is halved, energy is also halved.
Do you believe that in 2020 every single American, regardless of race, sex, or income level, has an equal opportunity to achieve his/her American Dream? Why or why not?
Answer:
Tbh i rlly dont think that many will. Most may succeed in doing so. But i mean come on its 2020 anything can happen.
Explanation:
Answer:
yes 100% what reasons r there to not tho
Explanation:
2.18 x 10^6 ng = 2.18 x 10^? mg
Answer:
2.18 * 10^12 mg
Explanation:
1 nanogram [ng] = 10^6 milligram [mg]
2.18 * 10^6 ng/ 1 ng = X mg / 10^6 mg
X mg = 2.18 * 10^12 mg
Answer:
2.18 * 10^12 mg
Explanation
8. What is Planck's law?
O F = hm
O F = MA
O E = hf
O E = mc (squared)
Answer:
O E = hf
Explanation:
Which example best demonstrates stewardship of the atmosphere
Incomplete question. However, I provided a specific example of stewardship of the atmosphere.
Explanation:
First, note that the term stewardship refers to the belief that humans are obligated to take care and look after our environment (which includes the atmosphere.
An example of this is: deciding to change our mode of transportation: What this entails is that we may decide to switch to riding a bicycle to places rather than going by car. By so doing you will be reducing the number of greenhouse gases emitted into the environment as bicycles do not emit harmful gases when used.
how would you differentiate between acid and bases if the list of their chemical formula is given to you
HELPPPP I WILL GIVE YOU BRAIN THINGG WHATEVER ITS CALLED
We have learned that there are five steps to reading a new piece of music. Can you name all five steps?
Notes, Pitches, Articulation, Phrasing, and Musical Extras.
The Tacoma narrows bridge collapsed due to?
A. Refraction
B. Reflection
C. Diffraction
D. Resonance
Which chemical equation best represents the Law of Conservation of
Mass?
O H+ 0 -> H20
H2 + 02 --> H20
2H2 + O2 --> 2H20
H2 + O2 --> 2H,02
2H₂ + O₂ ⇒ 2H₂O
Further explanationConservation of mass states that
In a closed system, the masses before and after the reaction are the same
So it can be concluded
mass of the reactants = mass of the productsmass cannot be created or destroyedThe number of atoms involved in a reaction remains the same⇒ number of moles also the samechemical equation in balanced formSo let's see which of the several options , which one has the same number of atoms on both sides of the equation
2H₂ + O₂ ⇒ 2H₂O
H ⇒ left 4, right 4
O ⇒ left 2, right 2
so the equation is in balance and represents the Law of Conservation of
Mass
Annalise observes a streak of light in the sky and says she is seeing a shooting star. What is she most likely observing?
a falling star
an asteroid
a meteor
a dwarf planet
Answer: A Meteor
Explanation:
A streak of light in the sky and says she is seeing a shooting star. She's most likely observing is a meteor. Therefore, option C is correct.
What is a meteor ?A meteor is an object from space or a meteoroid that touches down on Earth. The air on the space rock creates drag that causes it to become incredibly heated as it falls toward Earth.
When the earth travels through cometary debris during its orbit around the Sun, meteor showers will result. Although the Earth's orbit around the Sun is nearly round, the majority of comets have very elliptical orbits.
A meteoroid becomes a meteor, or a streak of light in the sky, if it gets close enough to Earth and enters its atmosphere. These light striations are sometimes referred to as "shooting stars" due to their appearance. However, stars are not what meteors are.
Thus, option C is correct.
To learn more about meteor, follow the link;
https://brainly.com/question/11504264
#SPJ2
please help asappp
will mark branliest!!
Answer:c
Explanation:
Answer:
C is the answer
are in the outermost energy level
Complete a write up about the elements in Ammonia and explain how the elements bounded to create the new substance.
Answer:
Explanation:
Ammonia consist of nitrogen and hydrogen.
Chemical equation:
N₂ + H₂ → NH₃
Balance chemical equation:
N₂ + 3H₂ → 2NH₃
We can see that nitrogen and hydrogen react with each other and from ammonia.
Nitrogen is present in group 5A. The atomic number of nitrogen is 7. Its atomic mass is 14 amu. It has 5 valence electron.
Electronic configuration:
N₇ = 1s² 2s² 2p³
we can see there are five electron in outer most shell. Thus, nitrogen needs three more electrons to complete the octet. When it combine with other atoms it gain three electron from them
While hydrogen is present in group 1A. It has one valence electron. In ammonia (NH₃) when nitrogen react with hydrogen it gain three electrons thus three atoms of hydrogen combine with one atom of ammonia because one hydrogen atom can share only one electron. Covalent bond is formed between nitrogen and hydrogen and new substance formed is called ammonia.
Convert the following to Celsius
6) 32°F
7) 45°F
8) 70°F
9) 80° F
10) 90° F
11) 212°F
9. (80-32)5/9
48×5/9
240/9
26.66°C
9. (90-32)5/9
58×5/9
32.22°C
10 (212-32)5/9
180×5/9
20×5
100°C
Examine the layers of rock. Identify and explain which layer contains the youngest fossils.
Earth layers with fossiles in each labeled top to bottom A to D.
Answer:
Layer A is the youngest
Explanation:
It is at the top, it has all of the dinosaur bones which got buried after earth got hit with an asteroid and they went extinct. Layer D started it and all of these years dirt, soil, and fossils have been gathering making each layer before older and older.
How
myny moles are present in 5.6x1022 atoms of Ne? (0.09 moles Ne)
Sot ne10.05
Answer:
mole = no of atoms/ 6.02E23.... so therefore answer= 5.6E22/6.02E23= 0.093✨
You are a high school track & field coach and you have a young female athlete who is running a competitive mile pace (5:20). This would make her competitive at the state and national level. You want to help this athlete to maintain and even increase her competitive potential. What would you do?
Answer:
By ensuring she is giving speed endurance training
Explanation:
Speed endurance training would be the most ideal in helping an athlete to maintain and even increase her competitive potential.
The speed endurance training would help the athlete maintain and attain a high speed for a longer duration of time.
This would make the athlete get used to running an improved time for much longer distances.
Which statement best describes the difference between veins and arteries? *
veins carry oxygen rich blood back to the heart while arteries carry oxygen poor blood
away from the heart
veins carry oxygen poor blood back to the heart while arteries carry oxygen rich blood
away from the heart.
brings oxygen into the lungs and releases carbon dioxide and water (waste materials)
from the body
arteries carry blood that is carbon dioxide rich to the heart,
Answer:
Veins carry oxygen poor blood back to the heart while arteries carry oxygen rich blood