Answer:
See explanation
Explanation:
A coin is money made from metal stuff. Common coinage metals are copper, silver, nickel etc.
One consideration in coin production is the density of the coin. A coin of less density will have lesser mass and occupy a lesser volume. This makes it easier to carry the coin around.
Coins should therefore be made of low density metals so that they can easily be carried about.
Which pair has the stronger ionic bond:
- MgCl2 vs. NaCl2
- NaCl vs. LiCl
what does it mean for electrons to be excited
Answer:
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle.
Explanation:
Hope this helps.
Have a good night ma´am/sir.
Be safe!
which element has the largest atomic radii in the 3rd period of the periodic table?
Answer:
Sodium (Na)
Explanation:
Which one of the following reactions would produce the largest amount of heat
per mole of hydrogen?
A) C(s) + 2 H2 (g) CH4 (g) AH° = -74.9
kJ/mol
B) N2O (g) + 3 H2 (g) N2H4 (g)+ H2O (l)
AH° = -316.8 kJ/mol
C) 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6
kJ/mol
D) N2 (g) + 3 H2 (g) 2 NH3 (g) AH° = -91.8
kJ/mol
Answer:
C) 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6
kJ/mol
Explanation:
The magnitude of heat released in an exothermic reaction is shown by the magnitude of the change in enthalpy.
The more negative the enthalpy change of the reaction, the more the heat released by the process.
Hence, 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6 kJ/mol has the most negative value of enthalpy change hence the greatest amount of heat is released in this reaction.
The reaction which would produce the largest amount of heat per mole of hydrogen is; Choice C: 2H2(g) + O2 (g). ===> 2 H2O (l) AH° = -571.6
AH° = -571.6kJ/mol.
According to the question;
We are required to identify the reaction which would produce the largest amount of heat per mole of hydrogen.It is evident that all the reactions are exothermic; the reactions release heat.
In essence, the reaction which produces the largest amount of heat is that with the largest negative enthalpy change, AH.In this scenario; the reaction that would produce the largest amount of heat per mole of hydrogen is Choice C: 2H2(g) + O2 (g) =====> 2 H2O (l) AH° = -571.6 kJ/mol
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A system initially has a pressure of 12 atm and a volume of 9 L. What is the volume if the pressure is decreased to 6 atm?
Answer:
The answer is 18 LExplanation:
In order to find the volume , we use the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the final volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
From the question
P1 = 12 atm
V1 = 9 L
P2 = 6 atm
We have
[tex]V_2 = \frac{12 \times 9}{6} = \frac{108}{6} \\ [/tex]
We have the final answer as
18 LHope this helps you
A given volume of gas at a temperature of 100 K has a
pressure of 225 kPa. At a higher temperature, the same
volume of gas has a pressure of 450 kPa. At what
temperature does the gas have this higher pressure?
Answer:
200K
Explanation:
Pressure is directly proportional to temperature.
100=225
x=450
(100*450)/225=x
x=45000/225
x=200
What is the density (g / mL) of a substance that has a mass of 8.11 g and, when placed into a graduated cylinder, causes the water level to rise from 25.26 mL to 44.72 mL?
Answer:
The answer is 0.42 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 8.11 g
volume = final volume of water - initial volume of water
volume = 44.72 - 25.26 = 19.46 mL
We have
[tex]density = \frac{8.11}{19.46} \\ = 0.416752312...[/tex]
We have the final answer as
0.42 g/mLHope this helps you
When a solid is placed in a container and heat is applied, a phase change occurs. Watch the video and identify which of the following statements are correct.
a) The temperature increases while all of a liquid is converted to a gas.
b) The average kinetic energy of the system changes while all of a solid is converted to a liquid.
c) Temperature remains constant while all of a solid is converted to a liquid.
d) When heat is applied to a solid, the molecular motion decreases as the temperature increases.
e) When a solid is converted to a liquid, heat is absorbed.
Answer:
Temperature remains constant while all of a solid is converted to a liquid.
When a solid is converted to a liquid, heat is absorbed.
Explanation:
During a phase change, the temperature of the system remains constant. Recall that latent heat is defined as heat that causes a change of state without a corresponding rise in temperature of the system.
When a solid is converted to a liquid, latent heat of fusion is involved hence the temperature of the system remains constant throughout the process.
Similarly, heat is absorbed as intermolecular forces are broken up and the would converts to liquid.
Question 4
Volume is what type of physical property?
Define molecular mass. Calculate the molecular mass of calcium carbonate
and nitric acid.
Answer:
HNO₃ =63.0147 g/mol
CaCO₃ = 100.088 g/mol
Explanation:
Molecular mass:
It is the sum of all the atomic masses of the atoms of elements present in a molecule.
For example:
The formula of CaCO₃:
Calcium carbonate consist of one atom of calcium, one atom of carbon and three atoms of oxygen. Thus, its molecular mass would be,
CaCO₃ = 40.078 × 1 + 12.01×1 + 16.00×3
CaCO₃ = 40.078 + 12.01+ 48
CaCO₃ = 100.088 g/mol
The formula of HNO₃:
Nitric acid consist of one atom of hydrogen, one atom of nitrogen and three atoms of oxygen. Thus, its molecular mass would be,
HNO₃ =1.008 × 1 + 14.0067 ×1 + 16.00×3
HNO₃ = 1.008 +14.0067 + 48
HNO₃ =63.0147 g/mol
pleaseeeeeeeeeeee help me
Answer:
4740460000, or 4.74046*10^9
Explanation:
This is math i thnk
e means *10
[tex]5.63\cdot \:8.42\cdot \:10^{19-11}[/tex]
[tex]5.63\cdot \:8.42\cdot \:10^8[/tex]
[tex]10^8\cdot \:47.4046[/tex]'
<3
Red
ok so this is saying
5.63 x 10^19 * 8.42 x 10^-11 indicates a scientific notation
plug into your graphing calculator and you get 4740460000 but make it imto three sig figs so the answer is: 4.74 x 10^9
How many types of rocks can form from the rock cycle?
0 1
02
O 3
04
Answer:
Sedimentary, igneous and metamorphic
Metomorphic, heat and pressure
Sedimentary erosion and weather
Igneous magma and lave
So three!
12 PTS!! WILL GIVE BRAINLIEST!! DUE TODAY!!
The experiment is increasing and decreasing the amount of predators, pollution, and food to see how the cricket frogs will react.
Test variable (independent variable):
Outcome variable (dependent variable):
Control group:
Answer:
Test variable (independent variable): Predators, Pollution, Food.Outcome variable (dependent variable): Cricket Frogs.Control group: Beginning Frog Count
Explanation:
If pollution isincreased, then the cricket frog population will (stay the same) over the span offive years.If the amount of food available isincreased, then the cricket frog population will (increase) overthe span of five years.Procedure:The procedures are listed in your virtual lab. You do not need to repeat them here. Please be sureto identify the test variable (independent variable), outcome variable (dependent variable), andcontrol group for this experiment.
HURRY PLEASE HELP!! The combustion of methane begins with 1 carbon atom and 4 hydrogen atoms in the compound CH4 How many hydrogen atoms will be
found as a product?
A. 3
B. 4
C. 1
D. 2
Answer:
B, 4.
Explanation:
i just took this
Which molecule would have this shape?
Answer:
CO2
Explanation:
the subscript tells you how many of one element is used for this case there is one black atom and 2 red ones so you only need 1 carbon and 2 oxygens.
hope this helps. brainliest please?
Which of the following is a common sign that a chemical change has occurred?
Write the complete ionic equation for the reaction that takes place when aqueous solutions of strontium hydroxide and lithium phosphate are mixed.
Answer : The net ionic equation will be,
[tex]3Sr^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Sr_3(PO_4)_2(s)[/tex]
Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The given balanced ionic equation will be,
[tex]3Sr(OH)_2(aq)+2Li_3PO_4(aq)\rightarrow 6LiOH(aq)+Sr_3(PO_4)_2(s)[/tex]
The ionic equation in separated aqueous solution will be,
[tex]3Sr^{2+}(aq)+6OH^{-}(aq)+6Li^{+}(aq)+2PO_4^{3-}(aq)\rightarrow Sr_3(PO_4)_2(s)+6Li^+(aq)+6OH^{-}(aq)[/tex]
In this equation, [tex]Li^+\text{ and }OH^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]3Sr^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Sr_3(PO_4)_2(s)[/tex]
The complete ionic equation for the reaction between aqueous solutions of strontium hydroxide and lithium phosphate is:
3Sr²⁺(aq) + 6OH¯(aq) + 6Li⁺(aq) + 2PO₄³¯(aq) —> Sr₃(PO₄)₂(s) + 6Li⁺(aq) + 6OH¯(aq)
The complete ionic equation is simply an equation showing all available entities including the spectator ions present in the solution.
With the above information in mind, we shall write the complete ionic equation for reaction between aqueous solutions of strontium hydroxide and lithium phosphate. This can be obtained as follow:
In solution, strontium hydroxide, Sr(OH)₂ and lithium phosphate, Li₃PO₄ will dissociate as follow:
Sr(OH)₂(aq) —> Sr²⁺(aq) + 2OH¯(aq)
Li₃PO₄(aq) —> 3Li⁺(aq) + PO₄³¯(aq)
The reaction will proceed as follow:
Sr(OH)₂(aq) + Li₃PO₄(aq) —>
Sr²⁺(aq) + 2OH¯(aq) + 3Li⁺(aq) + PO₄³¯(aq) —> Sr₃(PO₄)₂(s) + 3Li⁺(aq) + 2OH¯(aq)
Balance the equation by writing 3 before Sr²⁺, 6 before OH¯, 6 before Li⁺ and 2 before PO₄³¯, to obtain the complete ionic equation as shown:
3Sr²⁺(aq) + 6OH¯(aq) + 6Li⁺(aq) + 2PO₄³¯(aq) —> Sr₃(PO₄)₂(s) + 6Li⁺(aq) + 6OH¯(aq)
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PLZ HELP HURRY PLZZZZZ WILL GIVE BRAINLIEST
Answer:
I think its b
Explanation:
50 POINTS PLEASE HELP!!
What was the volume of air that has a volume of 6.00L at 120870 Pa, if the original pressure was 250020 Pa?
Answer:
120876
Explanation:
What is the weight of 12.0 moles of water?
Answer:
216g H2O
Explanation:
H = 1
O = 16
H= 2 × 1 = 2
O= 1 × 16 = 16
16 + 2= 18g/mol
18g H2O = 1 mol
X g H2O = 12 mol
X × 1 = 18 × 12
X = 216 g/mol
The weight of 12.0 moles of water is determined as 216 g.
What is the weight of the water?The weight of water is determined from the molecular weight of water. The molecular weight of water is given 18 g/mol.
The weight of 12 moles of water is calculated as follows;.
W = nM
W = 12mole x 18 g/mol
W = 216 g
Thus, the weight of 12.0 moles of water is determined as 216 g.
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Using the formula Q = m x ^T x Cp, solve for energy, and round your answer to the correct number of sig figs and show all work:
1) How much heat is absorbed by 1210. g water (Cp = 4.184 J/g*C) when it is heated from 20*C to 45*C
Answer:
Q = 126.5 kJ
Explanation:
Given that,
Mass, m = 1210 g
Specific heat of water, c = 4.184 J/g°C
Initial temperature, [tex]T_i=20^{\circ} C[/tex]
Final temperature, [tex]T_f=45^{\circ} C[/tex]
We need to find the heat absorbed by water. The formula that is used to find the heat absorbed is given by :
[tex]Q=mc\Delta T[/tex]
Putting all the values in it we get :
[tex]Q=1210\ g\times 4.184\ J/g^{\circ} C\times (45-20)^{\circ} C\\Q=126566\ J\\\\\text{or}\\\\Q=126.5\ kJ[/tex]
So, the amount of heat absorbed is 126.5 kJ.
Round the value 44.981 g to three significant figures.
Answer:
45.0
Explanation:
Using the rules of rounding, we can round 44.981 to 45. We need that third sig fig though, so we add the trailing zero
The value 44.981 g to three significant figures is 45.0 g.
Significant figures, also known as significant digits, are the digits in a number that carries meaning in terms of precision and accuracy. They indicate the certainty or reliability of a measurement or calculated value.
To round the value 44.981 g to three significant figures, follow the rules for significant figures:
Identify the three most significant digits in the number. They are 4, 4, and 9.
Look at the digit immediately after the third significant digit. If it is 5 or greater, round up; if it is less than 5, round down.
In 44.981 g, the digit immediately after the third significant digit (9) is 8. Since 8 is greater than 5, round up.
Therefore, rounding 44.981 g to three significant figures gives us:
45.0 g.
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Which of these does not accurately describe the Wright brothers' first
airplane?
A. It had wings that flapped,similar to birds wings
B.it had powerful yet exceptionally lightweight engines
C.it was created after various designs were tested in a wind tunnel
D.it was created using the engineering process
Answer: A
Explanation:
it had wings that flapped, similar to birds' wings.
How many elements are in a isotope?
Answer:i believe 9-?
Explanation:
boron-10
boron-11
carbon-12
carbon-13
oxygen-16
oxygen-17
oxygen-18
chlorine-35
chlorine-37
Which element represents 16 protons and 16 neutrons
who can do my chemistry homework for 20$?? First come
Answer:
WTH? That is WOW....-_-
Answer:
wow
Explanation:
wow
✓7
Is it rational or irrational
Answer:
Irrational
Explanation:
:)
Answer:
It is irrational
Explanation:
Since 7 is a prime number, it has no square factors and its square root cannot be simplified.
PLZ HELP PLZ HURRY NO WRONG ANSWER PLZ ALSO WILL GIVE BRAINLIEST
An atom of an element contains 6 protons, 6 neutrons, and 6 electrons. An atom that is a different isotope of this element would contain —
A.
6 protons, 7 neutrons, and 6 electrons.
B.
6 protons, 6 neutrons, and 7 electrons.
C.
7 protons, 6 neutrons, and 6 electrons.
D.
7 protons, 7 neutrons, and 7 electrons.
Answer:
I dont lnow much about chemistry, but I believe it's either d or a. sorry if its wrong!
Which evidence did Alfred Wegener use as evidence for the Continental Drift Theory?
Group of answer choices
A)South America and Africa fit like a puzzle.
B)Matching fossils on different continents
C)Similar rock types on the East coast of North America and Western Europe
D)All of the above
Which is the most effective action for people to take in order to reduce greenhouse gas emissions? O taking the bus more often O using a car powered by fuel cells O driving a car only five days a week O using a car that travels farther on each gallon of gas
One of the most effective ways to reduce greenhouse gases is using a car powered by fuel cells.
What are greenhouse gases?The term greenhouse gases refers to those gases that lead to a rise in the temperature of the earth due to the re-radiation of infrared rays towards the surface of the earth.
It is very important to take vital steps in order to prevent the emission of these gases. One of the most effective ways to reduce greenhouse gases is using a car powered by fuel cells.
Learn more about greenhouse gases: https://brainly.com/question/14131369?
Answer:
Using a car powered by fuel cells
Explanation:
B On Edge
