Answer:
Phosphorus
Explanation:
Actually that's red Phosphorus
The matchstick contains potassium chlorate at topOn reaction between these when we slides them white Phosphorus is formed which burns the match sticksAnswer:
Option B. ( Phosphorus)
Explanation:
Here, we want to select the option which is the main component present in the striking surface of a matchbox
The correct choice here is phosphorus
Red phosphorus which is an allotrope of phosphorus finds use in this particular case. It is the main chemical component present in the striking surface of a matchbox.
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A quantity of helium gas occupies 5 liters at room temperature and standard atmospheric
pressure (760 mm Hg). If the temperature stays the same, what will be the volume o
the helium if the pressure is increased to 950 mm of mercury?
The new volume of occupied by helium gas when its pressure is increased from 760 mm Hg to 950 mm Hg at an initial volume of 5 L is equal to 4 L.
Boyle's LawBoyle's law state that at constant temperature, the volume of a fixed mass of gas is directly proportional to its pressure.
To calculate the volume of the helium gas, we use the formula below.
Formula:
P₁V₁ = P₂V₂............. Equation 1
Where:
P₁ = Initial pressureV₁ = Initial volumeP₂ = Final pressureV₂ = Final volume.Make V₂ The subject of the equation
V₂ = P₁V₁/P₂............... Equation 2From the question,
Given:
P₁ = 760 mm HgV₁ = 5 LP₂ = 950 mm HgSubstitute these values into equation 2
V₂ = (760×5)/950V₂ = 4 L.Hence, The new volume of occupied by helium gas when its pressure is increased from 760 mm Hg to 950 mm Hg at an initial volume of 5 L is equal to 4 L.
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Hello people ~
One of the advantages of nylon over rayon is that nylon:
A. Is wrinkle free.
B. Has low elasticity
C. Is a natural fibre
D. Is a good conductor of electricity
Answer:
I think it is D.
Explanation:
Sry if I am wrong...
Answer:
wrinkle free
Explanation:
Nylon fabric is easy to wash so it's wrinkle free.Nylon is highly elastic and waterproof fabric.So it's highly used by mountaineers .What type of energy is shown in the circled portion of the graph? *
Answer:
Thermal Energy
Explanation:
Energy that is dissipated or absorbed as heat is in the form of thermal energy.
Hello people ~
When a cracker is ignited, a sudden reaction takes place with the evolution of heat, light and sound. Identify the type of combustion?
A. Random combustion
B. Rapid combustion
C. Spontaneous combustion
D. Explosion
D. explosion
When a cracker is lit, a rapid response results in the development of large amount of energy of heat, light, and sound. Explosion is the term for such a reaction.
Answer:
D. Explosion
Explanation:
Here, we want to identify the type of combustion characterized by the given properties
From what we have, there is a sudden reaction that takes place as the cracker is ignited
The type of combustion here is called Explosion
It takes place suddenly with the evolution of light, heat, and sound upon ignition.
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What does an electromagnetic spectrum refer to?
What are the three major branches of natural science?
• Earth and space science, life science, physical science
•Earth and space science, physical science, chemistry
•Physical science, life science, chemistry
•Life science, chemistry, physics
Explanation:
The three major branches of natural science are1.Physical,the study of universe.2.Chemistry,the study of matter.3.Biology,the study of life and living or organisms.have a good day.I hope this answer can help youAnswer:
here:)
Explanation:
Natural Sciences is the core of the branches of science as studies the nature of our physical world and the universe. The three branches of Natural Sciences are:
Physics, the Study of Universe.
Chemistry, the Study of Matter.
Biology, the Study of Life and Living Organisms.
A radioactive element has a half-life of six days. What is the approximate decay rate of the element after the first day? 0. 9% 1. 5% 8. 3% 10. 9%.
A radioactive element has a half-life of six days then the approximate decay rate of the element after the first day is 8.3%.
What is the half life time?Half life time is that time during which half of the concentration of reactant will changed into the product.
According to the question:
In 6 days = 50% of the reactant will change into product
In 1 day = 50%/6 of the reactant will change into product
So, in 1 day = 8.3% of the reactant will change into product
Hence option (3) is correct.
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If the freezing point depression for a solution is 2. 5°c and kf = 4. 5°c/m, what is the molality of the solution?
Given the freezing-point depression for a solution is 2. 5 °C and the cryoscopic constant is 4.5 °c/m, the molality of the solution is 0.56 m.
What is the freezing-point depression?Freezing-point depression is a drop in the temperature at which a substance freezes, caused when a smaller amount of another, non-volatile substance is added.
The freezing-point depression for a solution is 2. 5 °C. We can calculate the molality of the solution using the following expression.
ΔT = Kf × b
b = ΔT / Kf = 2.5 °C / (4.5 °C/m) = 0.56 m
where,
ΔT is the freezing-point depression. Kf is the cryoscopic constant of the solvent.b is the molality of the solution.Given the freezing-point depression for a solution is 2. 5 °C and the cryoscopic constant is 4.5 °c/m, the molality of the solution is 0.56 m.
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The molality of a solution will be 0.56 m. if the freezing point depression for a solution is 2.5° C.
What is molality?Molality is the measure of the moles of any solute in a solution per unit kg of the solvent.
Given, the freezing-point depression for a solution is 2. 5 °C
The kf is 4.5° c/m
[tex]\rm \Delta T = Kf \times b\\\\b = \dfrac{\Delta T}{kf} \\\\b = \dfrac{2.5^ \circ C}{4.5 \circ C/m} = 0.56 m[/tex]
Where T is freezing point depression
kf is cryoscopic constant of the solvent
b is molality of the solution
Thus, the molality of the solution is 0.56 m.
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True or false: Energy is always transferred from high kinetic energy (temperature) too low kinetic energy (low temperature)
Answer:
true
Explanation:
Temperature is a measure of the average kinetic energy of the molecules, so energy would naturally be transferred from the molecules with more kinetic energy to the molecules with less kinetic energy
What can be told about the age of the fossils in the diagram?
A.
The fossils in layer 5 are the oldest, and the fossils in layer 1 are the youngest.
B.
The fossils in layer 1 are the oldest, and the fossils in layer 5 are the youngest.
C.
All of the fossils are the same age because they were all present during the same period.
D.
Nothing about the ages of the fossils can be determined from the diagram.
Name two elements that are extracted from
their compounds by electrolysis.
Answer:
Hydrogen and oxygen
Explanation:
This is the most common compound water
When water goes through electrolysis it produces two elementsH_2 and O_2The reaction is given by
H_2O-->H_2+O_2Answer:
Hydrogen and helium is the answer
Will autoionization of water be spontaneous at high temperatures
Answer:
100
Explanation:
Will autoionzation of water be spontaneous at high temperature
What is density? (1 point) the amount of space occupied by a substance or body O the quantity of matter contained in a substance or body o the amount of heat contained in a body o the degree of compactness of a substance
Answer:
density answer IS ....
Identify the equations that show ionization. check all that apply. upper n a upper c l (s) right arrow upper n a superscript plus (a q) plus upper c l superscript minus (a q). upper h upper c l (g) plus upper h subscript 2 upper o (l) right arrow upper c subscript 3 upper o superscript plus (a q) plus upper c l superscript minus (a q). upper o subscript 2 (g) right arrow upper o subscript 2 (a q). upper c upper o subscript 2 (g) plus 2 upper h subscript 2 upper o (l) right arrow upper h upper c upper o subscript 3 superscript minus (a q) plus upper h subscript 3 upper o superscript plus (a q). upper c a upper c l subscript 2 (s) right arrow upper c a superscript 2 plus (a q) plus 2 upper c l superscript minus (a q).
When an atom gains or donates electrons to form an ion is called ionization. Hydrochloric acid with water and carbon dioxide with water are the ionization reaction.
What are Ionization reactions?In ionization reactions, the chemical species undergo changes to gain or lose electrons to acquire charge.
The reaction between hydrochloric acid and water to yield hydronium ion and chloride ion, and the reaction between carbon dioxide and water to yield hydronium ion and bicarbonate ion is the example of ionization as electrons are donated and gained by the species.
Therefore, the ionization reaction results in the gain or loss of electrons.
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Answer:
B and D just did it
Explanation:
What color should appear when a properly cleaned nichrome wire is introduced into the flame?.
Answer: The color that will appear when the nichrome wire is properly cleaned and introduced into flame would be orange
what is double displacement reaction
Answer:
A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding affiliations.
Explanation:
From: Wikipedia
What will your grade be if you have an 80 and you got a 68 on your unit test
Answer:
Its would be a very low C or a high D
Explanation:
Depending on what your teacher says or if you only got part of a question wrong it would be a very low C or a high D.
What do dark read areas indicated on the map?
Answer: Classifies cultural features, such as populated areas, main roads, and boundaries, on older maps.
Use Lewis symbols to predict the formula for the
compound that forms between magnesium and
nitrogen
The lewis structure of Magnesium nitride places eight electrons around N. 3 of these electrons are provided by Mg to get a stable conformation.
What is the Lewis structure?The Lewis structure is a representation of electron pairs in bonds between the atoms that compose the molecule. It can also show the solitary electron pairs that remain for each atom.
Electrons
When adding the valence electrons of each atom, we get the total number of electrons in the molecule.
The valence value is the number of electrons placed in the last energetic level of the atom.
The compound that forms between magnesium and nitrogen is magnesium nitride, Mg₃N₂. This is a simple salt with an ionic bond between a metal and a non-metal element.
What are the Metalic atoms?They are elements that express a tendency to lose valence electrons to get a stable electronic configuration. When they lose electrons, they remain positively charged. These are cations with positive charges and lose the valence electrons of their last level.
Mg has 2 electrons in its last level, so to get a complete stable configuration (2e-), it needs to lose 2 electrons.
Mg has two positive charges Mg ²⁺
What are the non-metalic atoms?They are elements that gain electrons to complete their last level. These are the anions. When they get electrons, they remain negatively charged.
Because Nitrogen has 5 electrons in its last level, it needs to add 3 electrons. In this way, it gets to the complete stable configuration (8e-).
N has three negative charges N³⁻
So, to complete the Lewis structure, we need to add Mg ²⁺ and N³⁻.
We know that
Mg loses two electrons,N needs to add three electrons.According to this, N needs more than one Mg to complete its last level.
So, in our calculations, we need to have three Mg and two N.
Two N need six electrons (-3e- x 2 = -6e-) to complete their last levelThree Mg can provide six electrons (+2e- x 3 = +6e-)You will find the final Lewis structure in the attached files.
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Pls help A student studies the effect of an object's height on its amount of gravitational energy. This graph summarizes the data from the study. Which statement best describes what the graph shows? A. As height increases, gravitational energy decreases. B. As height increases, gravitational energy increases. C. As height increases, gravitational energy increases exponentially. D. As height increases, gravitational energy decreases exponentially.
Answer:
B, as height increases gravitational energy increases
Water is a ______ molecule and the bond between the h-o is a __ ______ bond.
i know the last 2 is polar covalent bond but i don't know
the first blank.
Answer: polar molocule
Explanation:
Using the data below, what would be the independent variable?
Height of foam
Type of soda
Number of mentos
Color of mentos
Answer:
Number of mentos
Explanation:
i took the quiz
How does matter change its phase?
Explanation:
the answer can be in liquid, solid and gas
Calculate the molarity of a solution prepared by dissolving 0.2 mol sucrose in enough water to make a 100 ml solution.
Taking into account the definition of molarity, the molarity of a solution prepared by dissolving 0.2 mol sucrose in enough water to make a 100 mL solution is 2 [tex]\frac{moles}{liter}[/tex].
Definition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Molarity in this caseIn this case, you have:
number of moles= 0.2 molesvolume= 100 mL= 0.1 LReplacing in the definition of molarity:
[tex]molarity=\frac{0.2 mole}{0.1 L}[/tex]
Solving:
molarity= 2 [tex]\frac{moles}{liter}[/tex]
Finally, the molarity of a solution prepared by dissolving 0.2 mol sucrose in enough water to make a 100 mL solution is 2 [tex]\frac{moles}{liter}[/tex].
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How long do peeled boiled eggs last in the refrigerator?.
Answer:
approximately 1 week
Explanation:
Hope this helps, feel free to give feedback
1 to 2 weeks but if they smell a litte more stink then usually you better get rid of them or they my make you sick. i got sick for old boiled egg from the school cafeteria a long time ago.
Explanation:
What are two ways continents can grow?
Answer:
What are three ways continents get bigger?
age of rocks.
fossils.
evidence of melting (subduction)
location on current continents.
glacial deposits.
Perform the following operation
and express the answer in
scientific notation.
9.2x10^7 ÷ 3.7x10^9
Answer:
coefficient green : 2.4865
exponent (yellow) : 16
Explanation:
Explain what the color change indicated about the changes in the concentrations of Co(H2O) 6 2+ and CoCl 4 2- in each trial?
The color of the system will change between pink and blue depending on the concentration of species.
What is equilibrium?Equilibrium is attained in a reaction when the rate of forward reaction is equal to the rate of reverse reaction. Now consider the equilibrium;
Co(H2O)6^2+(aq) + 4Cl^-(aq) ⇄ CoCl4^2-(aq) + 6H2O(l)
We know that Co(H2O)6^2+(aq) is pink while CoCl4^2-(aq) is blue hence, if the concentration of the species are changed, the color of the system will change accordingly.
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Stirring iced tea mix into water is a chemical change?
Answer:
true
Explanation:
it changes the chemicals in the water and adds new ones
Why water is known as the "universal solvent?"
A. Because of water's polarity, it is not able to dissolve or dissociate many particles.
B. Because water is a polar molecule, it is able to dissolve or dissociate many particles.
C. Because water is a nonpolar molecule, it is able to dissolve or dissociate many particles.
A. I not sure kinda. Hopefully it's correct