Answer:
Celestial Sphere
Explanation:
When you look at the night sky, the stars appear to be fixed to an apparently curved surface above the observer. This surface is called the celestial sphere.
plz brainiest, thx, hope this helped
Plzzzzz help... What causes specific lines to appear in a line spectrum?
Answer:
Spectral lines are produced by transitions of electrons within atoms or ions. As the electrons move closer to or farther from the nucleus of an atom (or of an ion), energy in the form of light (or other radiation) is emitted or absorbed.…
Explanation:
Specific lines appear in a line spectrum because produced by transitions of electrons within atoms or ions.
What are spectral lines?Spectral lines are produced when the electrons undergoes transitions within atoms or ions. When the electrons move far or near to nucleus of any atom, radiation of particular wavelength is emitted or absorbed.
These emitted light is represented as they are moving from one state to the another.
Thus, specific lines appear in a line spectrum because produced by transitions of electrons within atoms or ions.
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True or false when matter changes it’s state it is a physical change because it is the same substance the whole time.
Answer:
true
Explanation:
A gas has a volume of 10 L at 200 K and a pressure of 1.5 atm . What would the volume of the gas be at 300 K and 2atm of pressure ?
Answer:
hi
Explanation:
I'm just figuring this out what am I doing
HELP ME!!! Is it right? Or wrong
Your bond Line notation is missing a carbon.
How many miles of N are in 0.179g of N2O?
Answer:
8.14x10⁻³ moles of N
Explanation:
In order to solve this problem first we convert 0.179 grams of N₂O into moles, using its molar mass:
0.179 g ÷ 44 g/mol = 4.07x10⁻³ mol N₂OThen we convert N₂O moles into N moles, using the data given by the compound's formula (that there are two N moles per N₂O mol):
4.07x10⁻³ mol N₂O * [tex]\frac{2molN}{1molN_2O}[/tex] = 8.14x10⁻³ mol NWhat is the volume of CO2 (acting as an ideal gas) if 64.0 mL of 1.261 M HCl reacts with excess
CaCO3 at 28 °C and 0.987 atm? Show your work and box your answer
2HCl + CaCO3 + H2O + CO2 + CaCl2
Answer:
1.01 L
Explanation:
Step 1: Write the balanced equation
2 HCl + CaCO₃ ⇒ H₂O + CO₂ + CaCl₂
Step 2: Calculate the reacting moles of HCl
64.0 mL (0.0640 L) of 1.261 M (1.261 mol/L) HCl react. The reacting moles are:
0.0640 L × 1.261 mol/L = 0.0807 mol
Step 3: Calculate the moles of CO₂ produced from 0.0807 moles of HCl
The molar ratio of HCl to CO₂ is 2:1. The moles of CO₂ produced are 1/2 × 0.0807 mol = 0.0404 mol.
Step 4: Calculate the volume occupied by 0.0404 moles of CO₂
0.0404 moles of CO₂ are at 28 °C (301 K) and 0.987 atm. We can calculate the volume occupied using the ideal gas equation.
P × V = n × R × T
V = n × R × T / P
V = 0.0404 mol × (0.0821 atm.L/mol.K) × 301 K / 0.987 atm = 1.01 L
Copper can be shaped into wires because it is
.ANSWER:Copper is a ductile metal
EXPLAIN :This means that it can easily be shaped into pipes and drawn into wires. Copper pipes are lightweight because they can have thin walls. They don't corrode and they can be bent to fit around corners.
Copper is a ductile metal due to ductility.This means that it can easily be shaped into pipes and drawn into wires. Copper pipes are lightweight because they can have thin walls.
Ductility is a mechanical property commonly described as a material's amenability to drawing (e.g. into wire).In materials science, ductility is defined by the degree to which a material can sustain plastic deformation under tensile stress before failure. Ductility is an important consideration in engineering and manufacturing. It defines a material's suitability for certain manufacturing operations (such as cold working) and its capacity to absorb mechanical overload.
Some metals that are generally described as ductile include gold and copper, while platinum is the most ductile of all metals in pure form.However, not all metals experience ductile failure as some can be characterized with brittle failure like cast iron. Polymers generally can be viewed as ductile materials as they typically allow for plastic deformation.
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18.0 g of carbon produces 55.0 g of carbon dioxide. What is the theoretical yield of CO2?
Answer:
Theoretical yield of CO₂ is 66 g
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated:
C + O₂ —> CO₂
Next, we shall determine the mass of C that reacted and the mass of CO₂ produced from the balanced equation. This can be obtained as follow:
Molar mass of C = 12 g/mol
Mass of C from the balanced equation = 1 × 12 = 12 g
Molar mass of CO₂ = 12 + (16×2)
= 12 +32
= 44 g/mol
Mass of CO₂ from the balanced equation = 1 × 44 = 44 g
SUMMARY:
From the balanced equation above,
12 g of C reacted to produce 44 g of CO₂.
Finally, we shall determine the theoretical yield of CO₂. This can be obtained as follow:
From the balanced equation above,
12 g of C reacted to produce 44 g of CO₂.
Therefore, 18 g of C will react to produce = (18 × 44)/12 = 66 g of CO₂.
Thus, the theoretical yield of CO₂ is 66 g.
Answer:
66 grams
Explanation:
How many non bonding electrons are on the central atom of a molecule of RnF4?
If 18.0 g of CO2 is produced in the reaction of C2H2 with O2 to form CO2 and
H2O, how many grams of H20 are produced in this reaction?
O 3.68 g
9.0 g
14.7 g
None of the above
7.37 g
Answer:
3.68 g
Explanation:
[tex]n_{CO2}[/tex] = 18 ÷ 44 = 0.4
2C2H2 + 5O2 → 4CO2 + 2H2O
2 : 5 : 4 : 2
0.409 (moles)
⇒ [tex]n_{H2O}[/tex] = 0.409 × 2 ÷ 4 = 0.2045 moles
⇒ [tex]m_{H2O}[/tex] = 0.2045 × 18 = 3.68 grams
Combustion, or __________, is an example of one of the most familiar chemical changes. Melting of ice, likewise, is one of the most common examples of physical changes. When a piece of coal burns, combines with the carbon in the coal. The products are carbon dioxide gas, water vapor, and a lot of ash. After careful measurements are taken, the of the reactants (coal and oxygen) is to the mass of the products (carbon dioxide, water vapor, and ash). During the_________ reaction, the quantity of matter is unchanged. Similarly, when 10 grams of ice__________ , grams of water is obtained. Mass is_________ in this change as well.
Answer:
a) Burning
b) physical
c) 10
d) constant
Explanation:
Mass remains same in a physical reaction. It changes only in chemical reactions where some of the mass is lost as energy /heat.
Thus, during combustion mass changes while during melting mass of water do not changes.
Even when the temperature of a pan of water is less than the boiling point, water still evaporates. This is because
a. the speeds of individual molecules varies
b. conservation of energy
c. of convection
d. radiation
Which of the following is NOT correct about the mole concept?
1 point
1 mole of sodium atoms will ionize to produce 1 mole of sodium ions and 1 mole of
electrons
A mole is the number of carbon atoms in 12g of C-12 isotope.
A mole is the number of molecules in 22.4 dm3 of all gases at all temperatures and
pressures
A mole is the number of electrons that carry one Faraday of electricity
A mole is the number of molecules of water in 18 g of ice, water or water vapour
Answer:
a mole is the number of molecules in 22.4 dm³ for all gases at all temperatures and pressures
4. The table shows the thermal conductivity of some common materials. Which would be the best insulator A. diamond B. gold C. lead D. concrete
please help me
The answer should be diamond.
Explanation:
Dry air is 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide so varying amounts of water vapor- depending on humidity. Some gases however strongly absorb infrared radiation and trap it in the atmosphere and can therefore result in elevated global temperatures. Therefore they are termed greenhouse gases. Which greenhouse gas have we observed a marked increase in atmospheric concentrations in the last 100 years?
A. methane (CH4)
B. carbon monoxide
C. carbon dioxide
D.ozone (03)
E. oxygen
F. nitrogen
G.water vapor (H20)
Answer:
C. Carbon dioxide
Explanation:
Carbon dioxide is one of the end-product of combustion reactions involving many fuels today.
With the rapid increase in urbanization and technological development, man demand for energy increased tremendously. The discovery of fossil fuels paved the way for the astronomical increase in the concentration of carbon dioxide in the atmosphere. The burning of fossil fuels like coal and oil invovles the process where the carbon atoms present in these fuels combine with oxygen in the air to make CO2. This has resulted in an increase in the concentration of atmospheric carbon dioxide (CO2).
The burning fossil fuels for electricity, industry, heat, and transportation are the major sources of the emossion of carbon dioxide.
Also, the cutting down of trees for paper production, building construction and for the establishment of settlements also increase the concentration of carbon dioxide in the atmosphere. Trees are help remove carbon dioxide from the atmosphere through the process of photosynthesis. However, when these trees are cut down, carbon dioxide accumulates in the atmosphere.
Si-4) AN= 14 AM= 28
e= n=
Answer:
have a good day
Explanation:
The galaxies pictured above would best be classified as
A barred galaxies
C irregular galaxies
B spiral galaxies
D
elliptical galaxies
Answer:
Spiral galaxies
Explanation:
Thermosetting polymers are less likely to be recycled than thermoplastic polymers because: Thermosetting polymers are less likely to be recycled than thermoplastic polymers because: Some other reason. They are so cheap that it is not worthwhile to recycle them. They cannot be re-melted by heating to form into new shapes. They are so durable that there are not enough thermosetting polymers in the waste stream to set up a recycling program.
Answer:
They cannot be re-melted by heating to form into new shapes.
Explanation:
Recycling refers to the process of melting a plastic and making it into another shape or size.
Thermoplastics can be softened repeatedly, melted and remoulded. Thermosetting polymers can not be softened, melted and remoulded once they are formed.
Hence, thermosetting polymers cannot be re-melted by heating to form into new shapes therefore they can't be recycled.
Which of the following chemical substances has diatomic molecules? a) carbon dioxide b) nitrogen c) ozone d) nitrogen dioxide
Answer:
C I think
Explanation:
Individual Laboratory Follow-up Questions a. Explain the purpose of the experiment. b. What are reasonable sources of error for determining calcium ion concentration by the titration process? c. Summarize the conclusions for your experiment in two to three complete sentences. Include the amount of calcium in your soil.
Solution :
a). In this experiments, we can determine the hardness of the water or [tex]$Ca^{2+}$[/tex] ion concentration in the sample.
b). The Possible errors are :
- During the weighing of calcium standard preparation, if the balance is not traced properly, it will cause an error.
- By dilution of standard from the stock will lead a dilution error of 0.1 mL for 100 mL.
- Misreading the liter values will give an error.
c). Depending upon the calcium content present in the soil, we conclude that the fertile percent of the soil as well as the mineral capacity of the soil.
Engineers find a new metal that is stronger than steel.. (so on)
Answer is : D "Collaborate with other engineers in the design of a plane made from this metal".
Answer:
Explanation:
same thing as normal plane. just replace normal metal with this new sick metal :cool:
also make sure it weighs a good amount and won't fall from weight... im confused was this already answered???
Answer:
Collaborate with other engineers in the design of a plane made from this metal
Explanation:
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2 What is the correct sequence of steps for the preparation of a pure sample of copper(II) sulfate
crystals from copper(II)oxide and sulfuric acid?
A dissolving → crystallisation → evaporation - filtration
B dissolving → evaporation filtration → crystallisation
Cdissolving → filtration - crystallisation - evaporation
D dissolving + filtration → evaporation → crystallisation
Answer:
The correct answer is - B. dissolving → evaporation filtration → crystallisation
Explanation:
The method of the preparation of a pure sample of copper(II) sulfate from dilute sulfuric acid and copper II oxide is given as follows:
step 1. Adding dilute sulfuric acid into a beaker. Using bunsen burner heat the beaker.
step 2. Adding the copper (II) oxide into the beaker and give it a little time at a time to the warm dilute sulfuric acid and stir
step 3. Filtering the mixture into an evaporating vessel to remove the excess copper (II) oxide and water from the filtrate.
Step 4. leave the rest filtrate to crystallize.
Copper (II) Oxide {CuO (s)} + Dilute Sulfuric Acid {H2SO4 (aq)} → Copper (II) Sulphate {CuSO4 (s)} + Water {H2O}
The correct sequence of steps for the preparation of a pure sample of copper(II) sulfate crystals from copper(II) oxide and sulfuric acid is dissolving → evaporation filtration → crystallisation.
Which form is the purest?Purest form of any substance is the crystalline form, if we get the compound in the crystalline form from any extraction then we get a pure sample.
Crystals of copper(II) sulfate, will get from copper(II) oxide and sulfuric acid through following steps:
First we put sulfuric acid in a beaker and then we warm in water bath.Then we add some powder of copper(II) oxide to the beaker, and will continue this adding till it is in excess.Then we filter the mixture and pour the filtrate of copper(II) sulfate into an evaporating basin and heat the solution evaporate half of the water.Then we pour the above solution into an evaporating basin & leave to allow all water to evaporate, and finally get the crystals of copper(II) sulfate.Hence, option (B) is correct.
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Which of the following equations is not balanced?
O 2NaHCO3 + H2SO4 -> Na2SO4 + 2H2O + CO2
O 2NO + O2 -> 2NO2
O Cu + 2AgNO3 -> Cu(NO3)2 + 2Ag
O 2Mg + O2 -> 2MgO
O CaCO3 -> CaO + CO2
Answer:
1 2NaHCO3+H2SO4->Na2SO4+2H2O+2CO2
Most physical and chemical changes in matter include a change of energy true or false
Answer: true
Explanation:
Energy changes are a common component of physical and chemical changes in matter. Hence the statement is True.
Briefing:Physical changes and chemical changes are the two different types of changes that chemists examine. A substance can undergo physical changes without having its identity altered. Chemical transformations take place when one substance transforms into another.
Which is a chemical change?When one chemical material changes into one or more others, as when iron rusts, this is referred to as a chemical transformation. Chemical reactions produce changes in the way that atoms and molecules are ordered, which leads to the formation of new substances with new properties.
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In an experiment, students were given an unknown mineral. The unknown mineral was placed in 150 ml of water. Once in the water, the volume went up to 165 ml. Then when the same object was dried, then massed on a balance. It had a mass of 225 grams. What is the density of the unknown mineral?
Note: You only have to fill in the numerical answer.
Answer:
15 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
But from the question
volume = final volume of water - initial volume of water
volume = 165 - 150 = 15 mL
We have
[tex]density = \frac{225}{15} = 15 \\ [/tex]
We have the final answer as
15 g/mLHope this helps you
What volume in milliliters of H20 you need during preparation of 100 milliliters of 14.00 M H2SO4 solution starting with bottle of 17.5 M H2SO4? (Round your answer to closest integer)
Answer:
20 mL
Explanation:
We can determine the required volume of the concentrated (17.5 M) H₂SO₄ solution by using the C₁V₁=C₂V₂ formula:
17.5 M * V₁ = 14.00 M* 100 mLV₁ = 80 mLAs out of the 100 mL of the final solution, 80 mL are from the concentrated H₂SO₄ solution, the remaining 20 mL are of water (H₂O).
How many grams of K2O can be made from 43 g of potassium and 32 g of oxygen from the following
equation?
4K + 02 --> 2K2O
Answer:
51.81g of K2O are produced
Explanation:
Based on the reaction, 4 moles of K reacts per mole of oxygen to produce 2 moles of K2O. To solve this question we must find the moles of each reactant in order to find the limiting reactant. With limiting reactant we can find the moles of K2O produced and its mass:
Moles K -Molar mass: 39.0983g/mol-
43g * (1mol / 39.0983g) = 1.1 moles K
Moles O₂ -Molar mass: 32g/mol-
32g * (1mol / 32g) = 1mol O₂
The moles required for the reaction of 1 mole of O₂ are 4 moles of K. As there are just 1.1 moles, K is the limiting reactant.
The moles and the mass of K2O produced are:
1.1moles K * (2mol K2O / 4mol K) = 0.55 moles K
Molar mass K2O = 94.2g/mol
0.55 moles K * (94.2g / mol) =
51.81g of K2O are produced2. Why is it difficult for us to go up in a mountain than go down?
A We are moving against gravity
B. We are pulled by the wind
C. We are moving towards gravity.
D. None of the above
Farth
help
Answer:
We are moving against gravity
Light and radio are examples of the __________________________ or ______________________ energy form, which is ________________ because it is always moving.
Answer:
Radiant; electromagnetic; kinetic energy.
Explanation:
Energy can be defined as the ability (capacity) to do work. The various forms of energy are solar energy, electrical energy, chemical energy, thermal energy, wind energy, nuclear energy etc.
The two (2) main types of energy are;
a. Gravitational potential energy (GPE): it is an energy possessed by an object or body due to its position above the earth.
b. Kinetic energy (KE): it is an energy possessed by an object or body due to its motion.
Light and radio are examples of the radiant or electromagnetic energy form, which is kinetic energy because it is always moving.
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
I need help with this because it's easy for you guys but I don't understand it
Answer:
from nitrogen fixation in plants, lightning and bacteria
Explanation: