Answer:
42
Explanation:
Because the proton number or atomic number is equal to electron number.
Answer:
42
In order for it to be neutral there must be the same amount of protons and neutrons
Have a nice day! :)
Select the correct answer
Which statement best supports the idea that water conservation is important for human societies?
OA Once humans use water, it cannot be reused ever again,
OB. Only about 1% of the freshwater on Earth is easily accessible.
OC Water is constantly being lost from the hydrosphere
OD. Most land animals use salt water instead of freshwater.
Answer:
Only about 1% of the freshwater on Earth is easily accessible.
Explanation:
Freshwater accounts for a minimal proportion of water resources on planet earth. About 70 percent of the world surface area is covered by water, but only about 2.5 percent of this mass of water is fresh. The remaining are marine or salt water. Amazingly, just about 1 percent of this freshwater is easily accessible. The other 1.5% is trapped in glaciers and snowfields.
This underscore the need for water conservation on the planet since fresh water is a scarce resource and people living in many areas have no access to fresh water.
You just got a free ticket for a boat ride, and you can bring along
2 friends! Unfortunately, you have 5 friends who want to come along.
Answer:
10
Explanation:
Khan Academy
I need help on Chemistry?
ANYONE PLEASE?
Answer:
1. 1g/ml
Explanation:
1. Density is mass divided by volume (g/mL).
10g/10mL = 1 g/mL
2. When you already know the density and the volume, you can use the density as a unit converter.
[tex]5mL*\frac{20g}{mL} = 100g[/tex]
3. It's the same with density and mass.
[tex]20g*\frac{1mL}{5g} = 4mL[/tex]
Two liters of hydrogen gas are stored at a
pressure of 100 kPa. If the temperature
does not change, what will the volume
of the gas be when the pressure is
decreased to 25 kPa?
Answer:
the volume will expand
Explanation:
gas under pressure contracts, and expands with a lesser pressure
The volume of the hydrogen gas at 25 kPa is 8 Liters.
Explanation:
Given:
At constant temperature, 2 liters of hydrogen gas at 100kPa pressure.
To find:
The volume of the hydrogen gas at 25kPa.
Solution:
The initial pressure of the hydrogen gas =[tex]P_1=100 kPa[/tex]
The initial volume of the hydrogen gas at 100 kPa =[tex]V_1=2 L[/tex]
The final pressure of the hydrogen gas =[tex]P_2=25 kPa[/tex]
The final volume of the hydrogen gas at 25kPa = [tex]V_2=?[/tex]
Using Boyles law:
[tex]P_1V_1=P_2V_2\\100kPa\times 2 L=25 kPa\times V_2\\V_2=\frac{100 kPa\times 2L}{25 kPa}=8L[/tex]
The volume of the hydrogen gas at 25 kPa is 8 Liters.
Learn more about Boyles law here:
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All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down an object, what is most likely true about the surface the object is moving on? The surface is dry. The surface is rough. The surface is uneven. The surface is smooth.
The question is incomplete, the complete question is;
All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down and object, what is MOST LIKELY true about the surface the object is moving on? (A) The surface is dry (B) The surface is rough (C) The surface is uneven (D) The surface is smooth
Answer:
(D) The surface is smooth
Explanation:
Friction exists because of relative motion between two surfaces in contact with each other. However the magnitude of friction depends on how rough or smooth the surface is.
For smooth surfaces, there is little or no resistance to motion as objects move over the surface. Hence objects take a longer time to slow down on a smooth surface due to very little friction.
On a rough surface, objects tend to slow down relatively quickly. Hence, less resistance to motion on a smooth surface makes an object to take a longer time to slow down on a smooth surface than on a rough surface.
Answer: D
Explanation: Because if the surface is smooth it causes it to be more even for it to be able to cause Friction
if you find this helpful, Your welcome, if not, sorry.
Nio conducts a science experiment. He puts yeast into a bottle with water and sugar, and then caps the bottle with a balloon. He returns two hours later and notices there are bubbles on the surface of the mixture in the bottle and that the balloon has inflated, but there are no other apparent changes.
What most likely happened?
a non-chemical change, because there are no indicators of chemical changes taking place
a chemical change, because the mixture changed color
a chemical change, because a gas was produced
a non-chemical change, because the changes that occurred are reversible
Answer:the answer is a chemical change, because a gas was produced
Explanation: yeast is a chemical
Answer:
The answer is C.
"Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions."
Explanation:
Can you explain what vsepr stand for in your own word?
which balances the equation Mg + O2 → MgO
Answer:
2Mg+[tex]O_{2}[/tex]→2MgO
Explanation:
The first step is magnesium + oxygen equals magnesium oxide
The second step is changing that into an equation which looks like Mg+[tex]O_{2}[/tex]→MgO
The third step is to 2*Mg and 2*O as well as the product has to be 2*Mg,2*O which gets the equation to become balanced as 2Mg+[tex]O_{2}[/tex]→2MgO
The coefficient 2 balance the given reaction. The balanced equation for the given reaction is given as [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex].
A balanced equation is a mathematical representation of a chemical reaction that respects the law of mass conservation. It depicts the reactants and products of the reaction, as well as the relative amounts of each species. The unbalanced equation is [tex]\rm Mg + O_2 \rightarrow MgO[/tex]. One magnesium (Mg) atom on the left side and one on the right side, so the magnesium is already balanced. Balance the oxygen (O) atoms. On the left side, there are two oxygen (O) atoms present in the O2 molecule. On the right side, there is only one oxygen (O) atom in the MgO molecule. To balance the oxygen atoms, we need to add a coefficient of 2 in front of MgO: [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex]. The balanced equation is [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex].
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Which option is an example of a chemical property?
A. boiling point
B. ability to react with oxygen
C. color
D. density
Answer:
boiling point
Explanation:
Option B
1. The human eye can detect wavelengths of light as short as 0.000037 cm. What is this
wavelength in nanometers?
Answer:
0.000037 cm is 370 nanometers
Explanation:
Which of the following atoms has the greatest ionization energy?
a.)W
b.)C
C.)d
P.)d
Answer:
helium
Explanation:
because there are no electrons screening it from the nucleus
Which statement best defines potential enregy?
A. Potential energy is stored energy.
B. Potential energy is energy that can change over time.
C.Potential energy is the energy of motion.
D. Potential energy is the type of energy a roller coaster uses.
Answer:
A. Potential energy is stored energy
Explanation:
Answer:
A
Explanation:
i have the same question
Write a balanced equation for the complete oxidation reaction that occurs when ethane burns in air
Alkanes are saturated hydrocarbons that have single bonds in chains
General formula for alkanes :
[tex]\tt \large{\bold{C_nH_{2n+2}}[/tex]
Hydrocarbon combustion reactions (specifically alkanes)
[tex]\large {\box {\bold{C_nH _ (_2_n _ + _ 2_) + \dfrac {3n + 1} {2} O_2 \Rightarrow nCO_2 + (n + 1) H_2O}}}[/tex]
So that the burning of ethane with air (oxygen):
[tex]\tt C_2H_6+\dfrac{7}{2}O_2\rightarrow 2CO_2+3H_2O[/tex]
2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)
or we can use mathematical equations to solve equilibrium chemical equations by giving the coefficients for each compound involved in the reaction
C₂H₆ (g) + aO₂ (g) ⟶ bCO₂ (g) + cH₂O (ℓ)
C : left 2, right b ⇒ b=2
H: left 6, right 2c⇒ 2c=6⇒ c= 3
O : left 2a, right 2b+c⇒ 2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2
1. True or False? The scientific method is defined as a method of research
in which a problem is identified, data is gathered, and a hypothesis is
created based off the data, then the hypothesis is tested.
Answer:
true
Explanation:
please mark BRAINLIEST
Why can two water molecules stick to each other?
HELPPP PLEASEEE!!! calculate the energy of radiation with a wavelength of 432 nm
Which of the following happens to the particles when the temperature of liquid water drops?
Explanation:
when water is in liquid form and the temperature DROPS it becomes solid ice the process is melting , freezing and evaporation this goes in a circle
Each water molecule can form hydrogen bonds with up to _____ neighbors
Group of answer choices
6
8
2
4
Answer:
2
Explanation:
thats the answer.have good day
Consider the reaction below. 2 Upper N Upper H Subscript 3 (g) Baseline double headed arrow Upper N Subscript 2 (g) Baseline + 3 Upper H Subscript 2 (g). What is the most likely effect to the forward reaction if there is an increase in pressure on this reaction? The reactant surface area increases. The reaction rate decreases. The reaction is not affected at all. The reaction stops completely.
Answer:
The increase in pressure of the reacting system will increase the formation of NH₃
Explanation:
The given parameters are;
2NH₃ (g) ⇄ N₂ (g) + 3H₂ (g)
The number of molecules in the reactant side of the equation = 2 molecules
The number of molecules in the product side of the equation = 1 + 3 = 4 molecules
Avogadro's law states that equal volume of all gases at a given temperature and pressure contains equal number of molecules
Therefore, given that the number of molecules of the product are twice the number of molecules of the reactant, the volume of the product is twice the volume of the reactant
If the pressure is increased, at constant temperature by Boyles law, the volume will be reduced, favoring the formation of the low volume occupying NH₃
Therefore, the reverse reaction (formation of NH₃) will preferably occur.
Answer:
The answer is B
Explanation:
The other answer is incorrect. The correct Answer is B
Trust Me
Sugar is added to iced tea and the contents are stirred until all of the sugar dissolves. How would the tea now be classified?
what is the concept of the doppler effect?
What is involved in weathering?
Answer:
the answer is water.Hope this helps
PLZ ANSWER WILL GIVE BRAINLIEST ASAP
Given the data below, what substance does not show a reaction for any of the tests? Hint: (+)= reaction occurred, (-)= no reaction
unknown
salt
Corn starch
Gelatin
Answer:
Salt
Explanation:
It has all -
Sodium + oxygen
What colour is the flame produces
Answer:
Orange
Explanation:
I used google my b
Answer:
ORANGE
explanation:
Small pieces of sodium burn in air with often little more than an orange glow. Using larger amounts of sodium or burning it in oxygen gives a strong orange flame.
A foam square has a mass of 25 g and a volume of 90 mL. What is the density?
Answer:
The answer is 0.28 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
So we have
[tex]density = \frac{25}{90} = \frac{5}{18} \\ = 0.277777...[/tex]
We have the final answer as
0.28 g/mLHope this helps you
A runner completes a 400m race in 43.9s. What is his average speed?
Answer:
average speed around 9.1 meters/second
Explanation:
400 divided by 43.9
What is the volume of a weather balloon that has 39 grams of helium with a density 0.017 g/mL?
Answer:
The answer is 235.29 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question.
density = 0.017 g/mL
mass = 4 g
We have
[tex]volume = \frac{4}{0.017} \\ = 235.2941176...[/tex]
We have the final answer as
235.29 mLHope this helps you
Write the principle of separation of mixture.
Explanation:
Mixtures can be separated using a variety of techniques. Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material.
A piece of wood that measures 2.7 cm x 5.5 cm x 3.9 cm has a mass of 84 g what is the density of the wood
The density of the wood : 1.45 g/cm³
Further explanationDensity is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of density
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
ρ = density
m = mass
v = volume
Volume of the wood[tex]\tt V=2.7\times 5.5\times 3.9=57.915~cm^3[/tex]
density[tex]\tt \rho=\dfrac{m}{V}\\\\\rho=\dfrac{84~g}{57.915~cm^3}=\boxed{\bold{1.45`g/cm^3}}[/tex]
What is your carbon footprint?
the amount of carbon dioxide you use when recycling
the amount of oxygen put into the atmosphere due to your consumption of fossil fuels
the amount of carbon dioxide and oxygen in the atmosphere at any given time
the amount of carbon dioxide put into the atmosphere due to your consumption of fossil fuels
Answer:
c. .....................
Answer: the amount of carbon dioxide put into the atmosphere due to your consumption of fossil fuels
Your carbon footprint is the amount of carbon dioxide and other carbon compounds emitted, because of your use of fossil fuels.
Hope this helps!