Answer:
The reaction has a high activation energy
Explanation:
The burning of methane is a spontaneous reaction. Once the burning begins, the flame is able to sustain itself without any additional input of energy. It is an exothermic reaction in which energy is given out in the form of heat.
The reason why heat from the match is needed to start the burning of methane is that the activation energy of the combustion of methane is high. Activation energy is the energy that must be supplied in order for the collision of reactants to result in chemical reaction.
As long as the activation energy is high, the reaction can not occur without an external input of energy (e.g striking a match). Hence the answer.
what is the charge on a calcium (Ca) atom that contains 18e?
Answer:
Ca2+
Explanation:
Are assorted jelly beans heterogeneous or homogeneous
Heterogeneous, which means that they are not evenly combined.
The photo shows wires made of pure copper, an element
What would the smallest piece of copper be?
A. Copper atom
B. Mixture of different kinds of metallic elements
C. Copper molecule
D. Compound containing two or more elements
Answer:
B
Explanation:
I hope its right. I'm pretty sure.
Answer:
Explanation:
Copper Atom
You have a stock solution of HNO3 with a concentration of 4.5 x 10^-4 M. However, you need 275 ml of a 2.50 x 10^-5 M solution. How much of the stock solution will you need?
Answer:
15.28 mL
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M₁) = 4.5x10¯⁴ M
Volume of diluted solution (V₂) = 275 mL
Molarity of diluted solution (M₂) = 2.5×10¯⁵ M
Volume of stock solution (V₁) needed =.?
The volume of the stock solution needed can be obtained by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
4.5x10¯⁴ × V₁ = 2.5×10¯⁵ × 275
4.5x10¯⁴ × V₁ = 0.006875
Divide both side by 4.5x10¯⁴
V₁ = 0.006875 / 4.5x10¯⁴
V₁ = 15.28 mL
Therefore, the volume of the stock solution needed is 15.28 mL
Give answer fast (C)
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Any two difference between short sightedness and long sightednes
Explanation:
tala it is also called myopia lekhnu hai
Äni Arko MA it is also called hypermetropia .
Calculate the volume, in liters, occupied by 1.80 moles of H2 gas at STP.
Answer:
40.32L
Explanation:
So we know that 22.4 Liters is one mole of a gass so we can set up an equation to test that
1mole 1.8mole
_____ = _____
22.4L x
and then cross multiply so you get 40.32L
Answer:
40.32L
Explanation:
Just did worksheet
Select the correct answer from each drop-down menu.
Researchers stationed at different areas on a mountain and in a tunnel midway through the mountain boiled water at the same time. Even though the water at every station was at the same temperature, the pot at the top of the mountain started boiling before the others. Why?
Water boils when the vapor pressure is
the atmospheric pressure. The atmospheric pressure
at the top of the mountain.
Water boils when the vapour pressure is least the atmospheric pressure.
The atmospheric pressure is equal at the top of the mountain.
What is atmospheric pressure?The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth.
As we go up in altitude the air pressure becomes less. When the pressure decreases, it takes less energy to get the water molecules to escape the surface. So the temperature is less than it would be at sea level.
Air pressure is higher or greater at the bottom of a mountain. This is because the height of the air above that level is thicker than at the top.
Pressure is given by the equation, P=rho*g*h, where rho is the air density, g is the gravity value and h is the thickness of the air layer on top of the level where we are considering the pressure.
Therefore, as we can see, at the bottom of the mountain, the thickness h of air is greater, and so is the pressure.
Hence, water boils when the vapour pressure is least the atmospheric pressure and the atmospheric pressure is equal at the top of the mountain.
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Which of the following compounds is least soluble in water?
1) Copper (II) Chloride
2) Aluminum Acetate
3) Iron (III) hydroxide
4) Potassium Sulfate
Answer:
3) iron (iii) hydroxide
Explanation:
Which is the balanced equation for S8 + O2 → SO2?
S8 + O16 → 8SO2
S8 + O2 → S8 + O2
S8 + O2 → S8O2
S8 + 8O2 → 8SO2
Answer: S8 + O2 → S8O2: not 100% sure
Explanation:
A balanced chemical equation happens when the quantity of the particles is required on the reactants side is equivalent to the quantity is the molecules in the items side.
Explain in a short sentence how you can tell a reaction is a decomposition reaction.
Answer: A decomposition reaction occurs when one reactant breaks down into two or more products.
Mark me as brainilist pls
The prefix "semi-" means "partly". Based on your knowledge of the properties of elements, which kind of element is most likely used to make semiconductors?
liquids
metalloids
metals
nonmetals
Answer:
metalloids
Explanation:
The kind of element most likely used to make semiconductors are the metalloids.
These elements have properties between those of metals and non-metals in that they are not truly metals and are partly non-metals.
Under certain conditions they show features of metals or non - metals. The class of these elements are the metalloids. They are used to make semiconductors which are major components of electronics.3. What is the best description of an ionic bond?
A. electrostatic force of attraction between positive and negative ions
B. electrostatic force of repulsion between ions of the same charge
C. nuclear force of attraction between protons of different atoms
D. nuclear force of repulsion between protons of different atoms
which personal trait do scientists mainly depend upon when they design an experiment
Answer:
creativity is the personal trait that scientists mainly depend upon when they design an experiment.
Iron-containing minerals in rocks may combine with water and air to create rust. This is an example of
A. chemical weathering
B. mechanical weathering
C. abrasion
D. exfoliation
Answer:
A
Explanation:
chemical reaction are those type of reaction that are irreversible and a new substance is being formed therefore when the iron combine with water and air it leads to rusting.
How many hydrogen atoms Is needed for C4H8 to become saturated
Answer:
2 atoms
Explanation:
Because it contain one double bond
What is the density of an object with a mass of 125 g and a volume of 150 mL ?
Answer:
13
Explanation:
234567877
In which highlighted section of the periodic table in the diagram provided above are the elements whose atoms have 1 valence electron located?
A) a
B) b
C) c
D) d
Answer:
B.
Explanation:
What is chemical structure about?
Answer:
chemical structure determines the molecular geometry of ca compound by prtraying the arrangement of atoms and chemical bonds in the molecule..
Explanation:
hope this helps any <3
what is tetra atomic molecules?
Answer:
Explanation:
They are the molecules that are formed when four atoms chemically bond together.
Give two limitations of law of Constant Composition
Answer:
1.The law does not hold true if the different isotopes of the element are involved in making chemical compound.
2.The law is not applicable when elements combine in the same ratio but different compounds are formed.
What is the percent composition of Phosphorus in Li3PO3
Answer:
you will get 17.983 g of lithium for every 100 g of lithium phosphate.
Explanation:
69.7% is the percent by mass of Lithium in Li[tex]_3[/tex]PO[tex]_3[/tex]. A percent is obtained by multiplying the result by 100.
One approach to show the concentration for an element within a compound or component in a combination is as a mass percentage. The mass percentage is computed by dividing the total weight of the combination by the mass of each component and multiplying the result by 100%. The mass percent is calculated by dividing the mass that contains the compound and solute by the mass for the element or solute.
99.795g/mol = molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex]
6.94g/mol = molar mass of Li
mass percentage of Li=(molar mass of Li/molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex])× 100
=(6.94/99.7)× 100
=69.7%
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it takes a slug 20 minutes to travel from the grass to the trash can a trip of 15 meters. how far could the slug travel in 60 minutes
Answer:
45 meters
Explanation:
Did the math
what the correct answer
Answer:
Alkali metals are elements found in group 1 of the Periodic Table. Alkali metals are soft, malleable, ductile, and are good conductors of heat and electricity. They have low melting and boiling points compared to most other metals.
How is the rock in the deep mantle similar to the rock in the parts of the mantle nearest the surface? How is it different?
Answer:
Similarity: Rocks within the mantle contain more magnesium and iron than the ones in the crust.
Difference: Rocks in the deep mantle are under intense heat and pressure. In this case, they are semi-solid rocks that flow slowly. On the other hand, the part of the mantle that is nearest to the surface consists of rigid rocks. It has a lower temperature than the rocks in the deep mantle.
Explanation:
Rocks within the mantle contain more magnesium and iron than the ones in the crust.
What is Rocks?
Rocks in the deep mantle are under intense heat and pressure. In this case, they are semi-solid rocks that flow slowly.
On the other hand, the part of the mantle that is nearest to the surface consists of rigid rocks. It has a lower temperature than the rocks in the deep mantle.
According to geologists, a rock is a naturally occurring material made up of crystalline crystals of various minerals that have fused together to form a solid mass.
Therefore, Rocks within the mantle contain more magnesium and iron than the ones in the crust.
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"You learned about mixtures, especially solutions and the factors that affect their makeup and properties. Why is it important to know the properties of both solutes and solvents when preparing a solution that is expected to meet a certain need?
Does this involve a chemical change or a physical change? Explain."
Can u pls help me
Answer:
its due to the solvents being factored. to be prepared for the solution you would need a chemical change as the solvents get factored so this will mean that it will have a chemical reaction. in this case its slightly different so it will be called a chemical change as 2 different chemicals change and evolve.
Explanation:
Do your answers to the previous questions satisfy
the following statements?
A) The dependent variable is changed by the
independent variable.
B) The independent variable causes a change
to another variable.
C) The independent variable is not changed by
another variable.
Answer:
I put B&C
Explanation:
Why Do Some Things Stop While Others Keep Going?
Answer:because they run out of energy when it is transferred and to other objects, or their kinetic energy
Explanation:
What is the charge of the nucleus ? Why ?
Answer:
A nucleus is a positive charge
Explanation:
A nucleus is made up of protons and neutrons. Protons have a positive charge and neutrons have a neutral charge.
do pressure and temputer remain consant in earth interior
Answer:
no
Explanation: