What begins the combustion phase of a four-stroke engine cycle?
A. The air-fuel mixture is compressed.
O
B. An air-fuel mixture flows into the cylinder.
O
C. The air-fuel mixture is ignited.
O
D. The air-fuel mixture expands.
Answer: B
Explanation: The engine cycle begins with the intake stroke as the piston is pulled towards the crankshaft (to the left in the figure). The intake valve is open, and fuel and air are drawn past the valve and into the combustion chamber and cylinder from the intake manifold located on top of the combustion chamber.
Câu 3: Nêu phương pháp hóa học nhận biết các dung dịch không màu sau: (a) HCI, NaOH, H2SO,, NaCl. (b) HNO3. KOH, BaCl. Ca(OH)2. Ba(NO3)2 (c) MgCl2, KCl, CuCl2, FeCl3, FeCl2 (chỉ dùng một thuốc thử). (d) Na2CO3, BaCl2, NaNO3 (chỉ dùng một thuốc thử)
Answer:
uvo 8hih8hjfiuwubosbwbhp0heg
Helium is in group 18 of the periodic table. How is helium different from the other elements in this group?(1 point)
A _ Helium atoms have a full outer energy level, while atoms of the other elements in the group do not have a full outer energy level.
B _ Helium atoms have 2 electrons, while atoms of the other elements in the group all have 18 electrons.
C _ Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
D _ Helium atoms have valence electrons in the first energy level, while atoms of the other elements in the group have valence electrons in the second energy level.
The correct answer to the question is option C. Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
Group 18 of the periodic table are known as the noble gas family. Their outermost shell is completely filled.
Members of the group 18 includes:
1. Helium (He)
2. Neon (Ne)
3. Argon (Ar)
4. Krypton (Kr)
5. Xenon (Xe)
6. Radon (Rn)
Among this group, only Helium (He) has a valence electron of 2. Other members of the group has a valence electron of 8.
Helium is part of the group 18 because its outermost shell is completely filled by its 2 electrons.
Therefore, option C gives the right answer to the question as helium only have 2 valence electrons while other members of the group has 8 valence electrons.
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i know that one of them is multiple choice but i’m not sure which one it is.
Explanation:
1. neutrons
2. protons
3. protons and neutrons
4. neutrons
5. electrons
I'm not sure with 1 and 4, sorry :<
When a liquid flows slowly, which of the following is accurate regarding its
viscosity?
A. it has a low viscosity
B. it has a high viscosity
C. it has a negative viscosity
D. it has a neutral viscosity
Please help me. I will mark you as a brainleist.
Answer:
Your answer is in the attachment. Hope this helps you. Stay blessed.
Arrange the gases in increasing order of the number of atoms that make up its molecule, from left to right.
Cl₂-CH₄-SO₂-CH₂O-C₂H₄.
thank you!
Answer:
C₂H₄-CH₄-CH₂O-SO₂-Cl₂
Explanation:
The arrangement of gases in increasing order of the number of atoms that make up its molecule, from left to right, is C₂H₄-CH₄-CH₂O-SO₂-Cl₂.
What are gases?
Gas is one of the matters. It's invisible, and its particles are present very far away from each other. The atoms of the gas move randomly, and they are always in motion.
There are iii kinds of matter, solid, liquid, and gas. When there is a modification in temperature when there is a rise in temperature the solid becomes liquid and eventually, the liquid becomes gas.
The arrangement of gases in it increases the order of the number of atoms. So it can be identified by seeing the moles of elements that are shown in the chemical formula of gas.
Thus, the arrangement of gases is C₂H₄-CH₄-CH₂O-SO₂-Cl₂.
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can any one tell me same for ALCL3 I need it urgently plzzz
Lets Form bonds
Al=2,8,3
Lets Write actual configuration or modern
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^3[/tex]
It has valency +3Cl:-2,8,7Let's write configuration
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^23p^5[/tex]
It has valency -1Now Criss cross valency (Refer to attachment)
We get
[tex]\\ \sf\longmapsto AlCl_3[/tex]
what is atomic weight?
Answer: The sum of an atom's protons, neutrons, and electrons, with protons equal to 1 AMU each, and electrons are 0 AMU each.
Explanation: By convention, atomic mass of an element is calculated by adding the masses of it's protons, neutons, and electrons. By definition, protons and neutrons are assigned values of 1 "atomic mass unit," or AMU, each, and electons are so small that they are assigned a value of 0 AMU each. Thus, a carbon 12 isotope atom (6 protons, 6 neutrons, and 6 electrons) would have a total of (6+6+0 =) 12 AMU. Carbon-13 has an additional neutron, so it's mass is (6+7+0)= 13 AMU. Molecules are the sum of each of it's individual atoms.
What is an AMU in actual mass? The definition states that 1 AMU is 1/12 the mass of a sinlge Carbon 12 isotope. By defining it in this manner, independent laboratories can calibrate their own instruments with a universal standard. Yes, even the Klingons can calibrate in their own galaxy, far, far away. For those physicists who know the value of even small amounts of mass, 1 AMU is equal to 1.66054x10^-24 grams. Before you scoff, just be reminded that E=mc^2, so while m, mass, may be small, c^2 (speed of light squared) is very large.
Mg(s) + CuSO4(aq) → Cus) + MgSO4(aq)
What are the products?
Answer:
Products are copper and magnesium sulphate
Explanation:
[tex]{ \bf{A+B→C+D}}[/tex]
A and B are reactants
C and D are products
En la practica de la papa,¿a que atribuyes el hecho de la rapidez de reacción?
Answer:
El rendimiento de tubérculos de la papa es vulnerable a las altas temperaturas y se ve desafiado por el aumento asimétrico de las temperaturas diurnas y nocturnas. Este estudio tuvo como objetivo evaluar la fotosíntesis, el crecimiento de biomasa, la distribución de la masa de tubérculos y el rendimiento de tubérculo seco en papas cosechadas temprano que se cultivaron en el campo bajo condiciones de alta temperatura diurna y nocturna durante diferentes etapas de crecimiento.
Acrylonitrile and ethyl acetate have the same boiling point: 77.2°C. In one to two sentences, explain what outcome you would expect if a
mixture of these two substances were distilled.
plsss hurry!
Acrylonitrile and ethyl acetate can not be separated by simple distillation since they have the same boiling point.
Distillation is a separation technique in chemistry which can be applied only when the substances to be separated have different boiling points. The method relies on the difference between the boiling points of the components of a mixture in order to achieve separation.
Whereby Acrylonitrile and ethyl acetate have the same boiling point: 77.2°C, separation by distillation becomes impossible because the two substances are collected together.
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Write the molecular formula of sodium chloride and water
Give an example of a non-biological chemical reaction that involves carbon. Name the process that converts a solid compound into a gas.
Answer:
The process that converts a solid mcompound into a gas is sublimation.
E.g- dry ice, solid iodine and ammonium salts
when the above solid are heated, only particles which are found on the surface of the solid gain enough energy and break all forces of attraction and form a gas.
Explanation:
What series does the following compound belong to?
Measurements of the heights of various plants in an experiment are called
Answer:
Option 1 Data
Answer:
data
Explanation:
that is the answer
please 5 stars
Milk Souring
a
Chemical Change
b
Physical Change
Answer:
Chemical Change
Explanation:
It is a chemical change because milk is a substance and if it changes its molecular structure ,so it is a chemical change.
Negative effects on farming. Atleast 10 negative effects
(marks 10)
Answer:
climate change, dead zones, genetic engineering, pollutants, deforestation, soil degradation, waste, Over irrigation, salt buildup in soils, monoculture
Explanation:
Hopefully this'll help you!
What does science mean to you?
Answer:
The study of properties for all things living and non-living
What is the charge on an electron?
A.–1
B.0
C.+1
D.+2
Answer:
definitely A
because proton is +1
aluminum is above carbon in the reactivity series.Explain why the aluminum in aluminum oxide cannot be extracted using carbon.
Aluminum is too high in the electrochemical series (reactivity series) to extract it from its ore using carbon reduction. The temperatures needed are too high to be economic. ... The aluminum oxide has too high a melting point to electrolyse on its own. The usual aluminum ore is bauxite.
You push a shopping cart for fun with a force of 60N. If the shopping cart has a mass of 12kg, what is the acceleration on the cart
Answer:
[tex]\boxed {\boxed {\sf 5 \ m/s^2 }}[/tex]
Explanation:
We are asked to find the acceleration of a shopping cart, given the force and mass. According to Newton's Second Law of Motion, force is the product of mass and acceleration.
[tex]F= m \times a[/tex]
The mass of the shopping cart is 12 kilograms and the force is 60 Newtons. Let's convert the units for force. 1 Newton is equal to 1 kilogram meter per second squared, so the force of 60 Newtons is also 60 kilogram meters per second squared.
F= 60 kg*m/s²m= 12 kgSubstitute the values into the formula.
[tex]60 \ kg *m/s^2 = 12 \ kg \times a[/tex]
We are solving for the acceleration, so we must isolate the variable a. It is being multiplied by 12 kilograms. The inverse operation of multiplication is division, so we divide both sides by 12 kg.
[tex]\frac {60 \ kg *m/s^2 } { 12 \ kg}= \frac{12 \ kg \times a }{12 \ kg}[/tex]
[tex]\frac {60 \ kg *m/s^2 } { 12 \ kg}=a[/tex]
The units of kilograms cancel.
[tex]\frac {60 \ m/s^2 } { 12 }=a[/tex]
[tex]5 \ m/s^2 =a[/tex]
The acceleration of the shopping cart is 5 meters per second squared.
Identify the more polar bond in each of the following pairs of bonds:
a. HF or HCl
b. NO or CO
c. SH or OH
d. PCl or SCl
e. CH or NH
f. SO or PO
g. CN or NN
Answer:
a.HF
b.co
c.oH
d.pcl
e.NH
f.po
g.CN
a) Among HF or HCl the more polar bond is HF. b) Among NO or CO, the more polar bond is CO. c) Among SH or OH, the more polar bond is OH. d) Among PCl or SCl, the more polar bond is PCl. e) Among CH or NH, the more polar bond is NH. f) Among SO or PO, the more polar bond is SO. g) Among CN or NN, the more polar bond is CN.
To determine the more polar bond in each pair, we need to consider the electronegativity difference between the bonded atoms. The greater the electronegativity difference, the more polar the bond. Electronegativity is a measure of an atom's tendency to attract electrons towards itself in a chemical bond.
The electronegativity values (Pauling scale) for the elements involved in the bonds are:
H = 2.20
F = 3.98
Cl = 3.16
N = 3.04
O = 3.44
S = 2.58
P = 2.19
C = 2.55
a. HF or HCl
HF: Electronegativity difference = 3.98 - 2.20 = 1.78
HCl: Electronegativity difference = 3.16 - 2.20 = 0.96
The more polar bond is HF.
b. NO or CO
NO: Electronegativity difference = 3.04 - 2.55 = 0.49
CO: Electronegativity difference = 3.44 - 2.55 = 0.89
The more polar bond is CO.
c. SH or OH
SH: Electronegativity difference = 2.58 - 2.20 = 0.38
OH: Electronegativity difference = 3.44 - 2.20 = 1.24
The more polar bond is OH.
d. PCl or SCl
PCl: Electronegativity difference = 3.16 - 2.19 = 0.97
SCl: Electronegativity difference = 3.16 - 2.58 = 0.58
The more polar bond is PCl.
e. CH or NH
CH: Electronegativity difference = 2.55 - 2.20 = 0.35
NH: Electronegativity difference = 3.04 - 2.55 = 0.49
The more polar bond is NH.
f. SO or PO
SO: Electronegativity difference = 2.58 - 3.44 = -0.86
PO: Electronegativity difference = 2.19 - 3.44 = -1.25
The more polar bond is SO.
g. CN or NN
CN: Electronegativity difference = 3.44 - 2.55 = 0.89
NN: Electronegativity difference = 3.04 - 3.04 = 0
The more polar bond is CN.
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0.0702 divided by 1.35
Answer:
0.052
Explanation:
0.0702 / 1.35 = 0.052
will mark brainliest if correct
Answer:
1. Evaporation
2. Filtration
3. Distillation
4. Chromatography
Explanation:
[tex].[/tex]
A sunscreen preparation contains 2.70 % by mass benzyl salicylate. If a tube contains 6.0 oz of sunscreen, how many kilograms of benzyl salicylate are needed to manufacture 340 tubes of sunscreen?
We know that the sunscreen preparation contains a 2.7% by mass of Benzyl Salicylate. From this, we will find that they need 1.559 kg of Benzyl Salicylate to make 340 tubes of sunscreen.
The initial data means that if the total mass of sunscreen is M, then the mass of Benzyl Salicylate will be 2.7% of M, or:
(2.7%/100%)*M = 0.027*M
Now, we know that a tube contains 6.0 oz of sunscreen.
Then M = 6.0oz
A tube contains:
0.027*6.0oz = 0.162 oz.
Then in 340 tubes, we will need 340 times 0.162 oz of Benzyl Salicylate, this is:
340* 0.162 oz = 55.08oz
And we want this quantity in kg.
Knowing that:
1oz = 0.028kg
Then 55.08oz is 55.08 times 0.028kg:
55.08*0.028kg = 1.559 kg
So they will need 1.559 kg of Benzyl Salicylate to make 340 tubes of sunscreen.
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for class ten:
compare and contrast between Mendeleev's periodic table and Moseley's periodic table.
Answer:
Mendeleev’s periodic table is, based on the relation of elements’ properties as dependent on the atomic weight of the element. But the Modern periodic table considers atomic number as the fundamental property that decides the properties of elements.
The modern periodic table does correct the defects of Mendeleev’s periodic table. For example, in Mendeleev’s periodic table, in the element pairs, Argon-potassium, cobalt-nickel, tellurium-iodine and thorium and protactinium, elements with higher atomic mass precede the element with lower atomic weight. However, it is the right places for them but is against Mendeleev’s periodic law.
These elements atomic number shows the reverse order compared to atomic mass. The supposed to be wrong positions in Mendeleev’s table has the right explanation justifying their positions.
Classify the following properties of the element
silicon as chemical or physical properties:
a. blue-gray color
b. brittle
c. doesn't dissolve in water
d. melts at 1410°C
e. reacts vigorously with fluorine
We have that this how they differ
Physical properties
Blue-gray color BrittleChemical Properties
Doesn't dissolve in water Melts at 1410°C Reacts vigorously with fluorine
From the Question we are told that
Silicon properties:
a. blue-gray color
b. brittle
c. doesn't dissolve in water
d. melts at 1410°C
e. reacts vigorously with fluorine
Physical properties
This Refer to Properties that can be seen and Measured
While
Chemical Properties
This are Refers to the effect of the element in reactions
Therefore
Physical properties
Blue-gray color BrittleChemical Properties
Doesn't dissolve in water Melts at 1410°C Reacts vigorously with fluorineFor more information on this visit
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who started water conservation in himachal pradesh
Explanation:
There are government khatris as well, which are maintained by the panchayat. Kuhls are a traditional irrigation system in Himachal Pradesh- surface channels diverting water from natural flowing streams (khuds). A typical community kuhl services six to 30 farmers, irrigating an area of about 20 ha.
Classify vodka (composed of 50% water and 50% alcohol).
Answer:
Liquor
Explanation: