Answer:
hand picking
Explanation:
as stone is bigger in size we can see them with our eyes so we can handpick it
Answer:
The method of hand picking is used to separate undesirable substances such as small pieces of stones from wheat, rice and pulses. The food grains containing small pieces of stones are taken in a flat container. The pieces of stones are picked up from the grains by hands, one by one, and thrown away.23 Oct 2020
Calculate how many methane molecules and how many carbon and hydrogen atoms are there in 25 g of Methane?
From the formula of methane it is clear that one mole of methane has 4hydrogen atoms. So, 37.6×1023 hydrogen atoms are there in 25.0 g of methane. Therefore, 9.4×1023methane molecules and 9.4×1023 hydrogen and 37.6×1023carbon atoms are there in 25.0 g of methane.
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identify water resevoirs as usuable or unusuable on their current state
Which of the following is a correct statement about water?
A)Hydrogen bonding causes water to be strongly cohesive.
B)Hydrogen bonding causes water to have a low surface tension.
C)Water is a universal solvent because polar and nonpolar solutes can dissolve in it.
D) Water is less dense as a liquid than as a solid because of changes in bond structure.
Answer:
D) Water is less dense as a liquid than as a solid because of changes in bond structure.
Explanation:
I hope I was able to help!
Have a nice day :)
The correct statements about water is that hydrogen bonding causes water to be strongly cohesive and is less dense as a liquid and solid.
What is hydrogen bonding?It is bonding in between the hydrogen atom and most electronegative atoms like flourine, chlorine, oxygen atoms, etc.
In water molecule hydrogen bonding is present in the form of intermolecular as well as intramolecular force and makes it more cohesive to get attracted towards each other.Water molecule has a high surface tension, as a result of which it is able to form a drop of water.Water is not a universal solvent, else it is a polar solvent and able to dissolve only polar molecules.It is also true that water is less dense as a liquid than as a solid because of changes in bond structure.Hence water is less dense as a liquid than as a solid because of changes in bond structure and hydrogen bonding causes water to be strongly cohesive.
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calculate the pressure in atm of .68 mol of H at 298K and occupying 4.5 L
Answer:
3.7 atm
General Formulas and Concepts:
Atomic Structure
MolesGas Laws
Ideal Gas Law: PV = nRT
P is pressureV is volumen is number of molesR is gas constantT is temperatureExplanation:
Step 1: Define
Identify variables
[Given] n = 0.68 mol H
[Given] T = 298 K
[Given] V = 4.5 L
[Given] R = 0.0821 L · atm · mol⁻¹ · K⁻¹
[Solve] P
Step 2: Find Pressure
Substitute in variables [Ideal Gas Law]: P(4.5 L) = (0.68 mol)(0.0821 L · atm · mol⁻¹ · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = (0.055828 L · atm · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = 16.6367 L · atmIsolate P [Cancel out units]: P = 3.69705 atmStep 3: Check
Follow sig fig rules and round. We are given 2 sig figs as our lowest.
3.69705 atm ≈ 3.7 atm
sources of magnesium to plants
the element magnesium has 3 orbital and 3 electrons true or false
Answer: True
Explanation:
Struggling on this problem.
Answer:
4Al + 3O2 ----> 2Al2O3
Explanation:
first blank 4
second blank 3
third blank 2
Hydrazine, N2H4, reacts with dinitrogen tetroxide, N2O4:
2 N2H4 (l) + N2O4 (g) → 4 H2O (l) + 3 N2 (g)
When 0.10 mol of hydrazone reacts with 0.10 mole of dinitrogen tetroxide, which of the following quantities would be consumed or produced?
Select one:
Answer:(I)+3 N2(g) that is correct
Explanation:
balance the following equation.
C + H2 + 02 → C2H60
Answer:
4C + 6H2 + O2>>2C2H6OExplanation:
there must be equal number of carbons, hydrogen and oxygen between products and reactants
Indica en qué modelos se fueron descubriendo las partículas atómicas y las unidades en la que se expresan su masa y su carga eléctrica
Answer:
En total son 8 modelos, en la explicación los nombraremos por orden de antigüedad.
Explanation:
Modelo atómico de Demócrito (450 a.C.)
Modelo atómico de Dalton (1803 d.C.)
Modelo atómico de Lewis (1902 d.C.)
Modelo atómico de Thomson (1904 d.C.)
Modelo atómico de Rutherford (1911 d.C.)
Modelo atómico de Bohr (1913 d.C.)
Modelo atómico de Sommerfeld (1916 d.C.)
Modelo atómico de Schrödinger (1926 d.C.)
How many moles are in 4.01x10^24 particles?
Answer:
6.64
Explanation:
so moles
[tex] \frac{number \: of \: \: particles \: }{6.02 \times {10}^{23} } [/tex]
then do =4.01×10^24/6.02×10^23
you get the answer as 6.6445 u only need to write the answer to
3.S.F 6.64 moles
hope this make sense :)
Carbon (C): 1sH2sI2pJ
H=
I =
J =
Answer:
H =2; I = 2; J = 2
Explanation:
Carbon is element 6 in the Periodic Table.
Start at element 1 (H) and count from left to right until you reach element 6 (C).
You get the electron configuration
C: 1s² 2s²2p².
Thus,
H =2; I = 2; J = 2
If crystal growth does not start on its own after the solution in the flask returns to room temperature, identify the best ways to promote this process. Select one or more: Add a bit of solid as a seed crystal. Scratch the bottom of the flask gently with a stirring rod. Place the flask on a hot plate to evaporate some solvent. Add ice cubes to the solution.
Answer: The best way to promote the process are:
--> Add a bit of solid as a seed crystal.
--> Scratch the bottom of the flask gently with a stirring rod.
Explanation:
A crystal growth is seen is SUPERSATURATED solutions which contains more solute than it can normally dissolve at that given temperature. It is usually very UNSTABLE and capable of releasing the excess solute if disturbed, either by shaking or seeding with a tiny crystals.
Crystallization can be used for the separation of two salts with different solubilities as well as for purification of a soluble salt that contains insoluble solid impurities. Recrystallization improves the validity of the process. Crystallization can be initiated by:
--> Scratching the bottom of the flask gently with a stirring rod: scratching initiates crystallization by providing energy from the high-frequency vibrations.
--> Adding a bit of solid as a seed crystal: Seed crystals create a nucleation site where crystals can begin growth.
Analyze the following chemical combinations
a) MgO
b)CaCl2
c) Na2O
Which formula represents a hydrocarbon with a double covalent bond?
Answer:
c is the answer
step by step explanation is not
The formula which represent a hydrocarbon with a double covalent bond is C₂H₄.
Hence, option D is correct answer.
What is Double Covalent Bond ?A double covalent bond is a type of covalent bond which involves the sharing of two pairs of electrons.
What is Covalent Bond ?A covalent bond is a type of chemical bond that involves the sharing of electron pairs between the atoms.
Now lets check all options one by one
Option (A): CH₃Cl
In CH₃Cl carbon has 4 valence electrons and carbon shares its 1 electron each with three hydrogen atoms and carbon shares its 1 electron with chlorine. Here bonds are formed due to sharing of electrons between the atoms. Hence CH₃Cl is covalent bonded.
So, it is incorrect option.
Option (B): C₂H₃Cl
In C₂H₃Cl, here two carbon atoms form double bond but they not form covalent bond.
So it is incorrect option.
Option (C): C₂H₂
In C₂H₂, each carbon has 4 valence electrons and each carbon shares its one electron with each hydrogen atom here two carbon atoms are triple bonded.
So, it is incorrect option.
Option (D): C₂H₄
In C₂H₄, there are two carbon atoms and two hydrogen atoms, here two carbon atoms are double bonded.
So, it is correct option.
Thus, from above conclusion we can say that The formula which represent a hydrocarbon with a double covalent bond is C₂H₄.
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any artist out there?
I need help knowing what colors I should use for a painting.
you can explain your question i can help if i know it
Answer:
You could use red, blue, yellow, white, black, brown, green, orange, purple
Other useful colors:
Payne grey
Yellow or golden ocher
Titanium buff or raw titanium
Explanation:
The lightest particle among the following is :
The question is incomplete, the complete question is;
The lightest particle among the following is:
• Electron •Proton • Neutron • Alpha
Answer:
Electron
Explanation:
There three basic subatomic particles are electrons, protons and neutrons. Both protons and neutrons are found in the nuclear and both contribute towards the mass of the atom. The alpha particle has the same mass as the helium nucleus.
However, the electrons are found in orbiit and have a negligible mass compared to the mass of the protons and neutrons. The mass of the electron is about 9.11 × 10^-31 Kg. This makes it the lightest of all the particles listed among the options.
what's radioactivity with a clear definition
Question 9 (1 point)
If a mylar balloon is filled with gas to a volume of 2.9 L at a temperature of 20 degrees celcius and then heated with a heat gun to 150 degrees
celcius, what is the new volume (assume no air escapes the balloon)?
Answer:I’m not sure
Explanation:free trial
Para la siguiente reacción: 2NH 3(g) + CO 2(g) ———> (NH 2 ) 2 CO (l) + H 2 O (l) a) ¿Cuántos gramos de NH 3 se necesitan para formar 720 g de (NH 2 ) 2 CO? b) ¿Cuántos moléculas de agua se obtienen a partir de 9 litros de CO 2 ayudenme porfa
Answer:
a. 408g de NH3 son necesarios
b. 2.42x10²³ moléculas de agua se obtienen
Explanation:
a. Basados en la reacción, 2 moles de NH3 producen una mol de (NH2)2CO. Para resolver esta pregunta debemos convertir la masa de (NH2)2CO a moles. Estas moles a moles de NH3 y su respectiva masa:
Moles (NH2)2CO -Masa molar: 60.06g/mol-
720g * (1mol / 60.06g) = 11.99 moles (NH2)2CO
Moles NH3:
11.99 moles (NH2)2CO * (2mol NH3 / 1mol (NH2)2CO) = 23.98 moles NH3
Masa NH3 -17.031g/mol-:
23.98 moles NH3 * (17.031g / mol) = 408g de NH3 son necesarios
b. 1mol de CO2 produce 1mol de agua. Se debe convertir el volumen a moles usando PV = nRT. Estas moles = Moles de agua. 1mol = 6.022x10²³ moléculas:
Asumiendo STP:
PV = nRT; PV / RT = n
Donde P = 1atm a STP
V = 9L
R = 0.082atmL/molK
T = 273.15K a STP
1atm*9L / 0.082atmL/molK*273.15K = n
n = 0.402 moles CO2 = Moles H2O
Moléculas:
0.402 moles agua * (6.022x10²³ moléculas / 1mol) =
2.42x10²³ moléculas de agua se obtienenURGENT PLEASE HELPIf 25 grams of liquid water releases 75J of heat when water cools from 88 degrees Celsius what is the final temperature?
Answer:
HEY RUBY!! WE ARE BOTH FAILING!!!!!!!
Explanation:
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The electronegativities of carbon and sulfur are almost the same. Both elements form covalently bonded compounds with hydrogen. Why is hydrogen sulfide a polar compound while methane is a nonpolar compound?
a.Sulfur has a stronger attraction for electrons than does carbon
b.A hydrogen sulfide molecule has lone pairs of electrons
c.Sulfur forms ionic bonds with hydrogen while carbon forms covalent bonds
d.Sulfur ions are larger than carbon ions
Answer:
b. A hydrogen sulfide molecule has lone pairs of electrons
Explanation:
The presence of lone pairs indictates that the molecule will be polar unless its molecular geometry is linear or square planar. In the case of H2S, its shape is bent due to the lone pair and it is a slightly polar molecule.
Which BEST describes how the genetic color variation within the beetle population helps them to survive? A. The color variation helps them to locate food B. The color variation helps them avoid predators C. The color variation helps them compete for resources D. The color variation helps them find mates for reproduction
Answer: B
Explanation: The beetles would be able to use their genetic color to learn how to adapt to the environment and hide from predators.
The statement, that describes the genetic color variation within the beetle population helps them to survive is "the color variation helps them avoid predators."
What is genetic variations?Genetic variations that can exist in a human population include skin color, hair color, dimples, freckles, and blood type. Human skin tone is a classic changeable characteristic that is regarded to be adaptive. Natural selection can result in major changes in the appearance, behavior, or physiology of individuals in a group in a matter of generations.
What is color variation?Meiosis and sexual reproduction combine various alleles in novel ways to generate genetic variety once new alleles emerge. Because of natural selection, green beetles outnumber red beetles. Color diversity can involve camouflage, and beetles could utilize their genetic color to learn how to adapt to their surroundings and hide from predators.
Because this feature has a genetic foundation, the surviving beetles have progeny of the same hue. Brown coloring, which permits the beetle to have more offspring, becomes increasingly prevalent in the population.
Hence the correct option is B.
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number 2 pls help me :):)
Answer:None of the tunes make a correct statement the third choice is closed but may still dating the pencil operates broken because the light been to a zoo from a straight line when it across the boundary between air and water
Explanation:
1. What metal is oxidized in the most common dry cell?
zinc
iron
carbon
copper
Answer:
the correct answer is zinc
URGENT!! 7.(06.02 MC)
A list of changes is shown.
A. Temperature decreases
B. Intermolecular bonds become weaker
C. Melting
D. Intermolecular bonds
become stronger
E. Temperature remains constant
F. Temperature increases
G. Vibration of molecules slows down
H. Molecules vibrate faster
Which of the above changes would be accompanied by an increase of the kinetic energy of particles in a solid? (5 points)
1. A, B, C, and H
2. A, C, D, and G
3. B, E, F, and G
4. B, C, F, and H
Answer:
3.B,E,F and G
Explanation:
1.A,B,C and H
Answer:
4. B, C, F, and H
Explanation:
Which of the following has kinetic energy?
Answer:
c ) a gymnast doing a cartwheel. ........
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chemistry help best answer gets marked brainly
Answer:
C. The final substance in beaker A is a pure substance while in Beaker B is a mixture
Explanation:
A pure substance is a substance that contains a constant and definite proportion of a single substance. Elements and compounds are the two known pure substances while mixtures are substances of different compositions mixed together.
In this question, two beakers; A and B are said to contain different substances. Beaker A contains elemental sulfur (S) that forms a yellow powder while beaker B contains sand and water. From the explanation above, the final substance in beaker A is a pure substance (element) while in beaker B is a mixture of sand and water.
What charge would Balloon #2 have? How did you determine this?
Answer:I belive it would be attracted seeing as how there are more magmatic charges on that side of no 2 and how there are more positive charges on the middle side of ballon no1.
Explanation:
¿Cuál de las siguientes configuraciones globales corresponde a un elemento químico que se comporta como metal? 1 punto [He]2s2 2p6 [Ar] 4s2 3d2 4p3 [Ne]3s2 [Ar] 4s2 3d10 4p4
Answer:
[Ne]3s2
Explanation:
ahora tenemos que mirar cada una de las configuraciones electrónicas de cada átomo de cerca antes de tomar una decisión.
considerando la configuración electrónica más externa de cada una de las especies mostradas;
para la primera configuración, ns2 np6 corresponde a un gas noble.
para la segunda configuración ns2 np3 corresponde a un elemento no metálico del grupo 5.
para la tercera configuración, ns2 corresponde a un elemento metálico del grupo 2.
para la cuarta configuración, ns2 np4 corresponde a un elemento no metálico del grupo 6