Answer:
cemical change
Explanation:
Answer: A Solution
Explanation: A solution is made when a substance like salt is poured into water. The result would be a solution. Salt being a solid and water being a liquid.
A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain
Answer:
d. 10 million years
Explanation:
These are the options for the question
Choose one answer.
a. 2.5 million years
b. 5 million years
c. 15 million years
d. 10 million years
✓half-life of the radioactive substance= 5 million years
✓ Then for every 5 million years, original radioactive given (100%) percentage is reduced by factor of 1/2.
✓ 1st 5 million year; After the first 5 million years, the original radioactive is reduced as;
(100%) × 1/2 = 50% remains
✓2nd 5 million year: At 10 millions year, the 50% remaining radioactive is reduced by factor of 1/2
(50%) × 1/2 = 25% remains
Hence, at At 10 millions years 25% of the original radioactive atoms remain
.
Answer:
10 million years
Where and in what features is water found on Earth?
Answer: On Earth, liquid water exists on the surface in the form of oceans, lakes and rivers. It also exists below ground as groundwater, in wells and aquifers. Water vapor is most visible as clouds and fog. The frozen part of Earth's hydrosphere is made of ice: glaciers, ice caps and icebergs.
Which rule states that cracks on glass tend to form at a certain angle on the opposite side of the polnt of Impact?
The
rule states that cracks tend to form at a (n)
angle on the opposite side from the point of Impact.
Answer:
The 3R rule states that cracks tend to form at a (n) right angle on the opposite side from the point of impact.
Explanation:
PLEASE HELPP!
Question #9
Long Text (essay)
Summarize the arguments both for and against allowing genetically altered meats into the United States.
B
1
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I
© 2013 Glynlyon, Inc.
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Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.ENVIRONMENTAL RISK. STRONGER CROPS = LESS PESTICIDES. REMEMBER WHEN CIGARETTES WERE 'HARMLESS'? TAMPERING FOR TASTE. ...BIG BUSINESS EATS SMALL FARMERS. ENHANCED HEALTH. NOTHING TASTES BETTER THAN NATURE.Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.
ENVIRONMENTAL RISK.
STRONGER CROPS = LESS PESTICIDES.
REMEMBER WHEN CIGARETTES WERE 'HARMLESS'?
TAMPERING FOR TASTE. ...
BIG BUSINESS EATS SMALL FARMERS.
ENHANCED HEALTH.
NOTHING TASTES BETTER THAN NATURE.
Explanation:
Calculate the mass in grams for 2.28 moles of N2?
Mole measure the number of elementary entities of a given substance that are present in a given sample. The mass of [tex]N_{2}[/tex] with 2.28 mol is 63.84g.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. Mole is inversely proportional to the molar mass of respective molecule. 1 mole contains Avogadro number of atoms, ions or molecules. Mole is extensive property as it depends on the quantity of substance.
mole of [tex]N_{2}[/tex] =given mass of [tex]N_{2}[/tex] ÷molar mass of nitrogen gas
mass of [tex]N_{2}[/tex]= mole of [tex]N_{2}[/tex] ×molar mass of nitrogen gas
mole of [tex]N_{2}[/tex]= 2.28mol
Substituting the values in the formula we get,
mass of [tex]N_{2}[/tex]= 2.28mol ×28g/mole
mass of [tex]N_{2}[/tex]= 2.28mol ×28
mass of [tex]N_{2}[/tex]=63.84g
Therefore the mass of [tex]N_{2}[/tex] is 63.84g with 2.28 mole is 63.84g.
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which of these is an example of the climate of a region?
A. Dry
B. Foggy
C. Overcast
D. Sunny
its dry i think
Explanation:
it might be dry
an unknown substance has a mass of 57.4 g and occupies a volume of 34.3 ml. what is the density in g/ml?
Answer: 1.67
D=M/V
(D=57.4/34.3)= 1.67
6. 7. A hyperbaric chamber has a volume of 200. L. (a) How many moles of oxygen are needed to fill the chamber at room temperature (23°C) and 3.00 atm pressure? b) How many grams of oxygen are needed? (Hint: Since moles have been asked, which equation has the moles listed in the equation. Use that to solve this problem. Also don’t forget to use the equation 1 mole = Formula weight or Molecular weight to calculate the grams of O2).
Answer:
a) 24.7 mol
b) 790 g
Explanation:
Step 1: Given data
Volume of the chamber (V): 200. LRoom temperature (T): 23 °CPressure of the gas (P): 3.00 atmStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = 23°C + 273.15 = 296 K
Step 3: Calculate the moles (n) of oxygen
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 3.00 atm × 200. L/(0.0821 atm.L/mol.K) × 296 K = 24.7 mol
Step 4: Calculate the mass (m) corresponding to 24.7 moles of oxygen
The molar mass (M) of oxygen ga sis 32.00 g/mol. We will calculate the mass of oxygen using the following expression.
m = n × M
m = 24.7 mol × 32.00 g/mol = 790 g
which would be a stronger acid H3PO4 or H3PO2
Answer:
h3po2
Explanation:
Answer:
i think it is H3PO4
Explanation:
ANSWER QUICK !!!
How many grams of hydrogen gas will be produced if you start with 15.0 grams of zinc and an excess amount of HCI?
balanced equation:
Zn + 2HCI = ZnCl2 + H2
Answer:
uhh
ExplanatioUHHHHHHHHHHHHHHHHHHH
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How do atoms in molecules bond?
plz answer I will give brainliest
Answer:
Via covalent bonds
Explanation:
Atoms in molecules are bonded together via covalent bonds. Covalent bonds are bonds that are formed by sharing of the valence electrons between two atoms.
The atoms can be of the same kind or of different kinds.
In most molecules, the two atoms are connected by sharing of their valence electrons. This way, each atom can attain stability by becoming isoelectric with the nearest noble gas. Some molecules are monoatomic, some are polyatomic.6.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 26. g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured:
product mass
carbon dioxide 20.31g
water 4.16 g
Use this information to find the molecular formula of X
Answer:
C2H2
Explanation:
Mass of Carbon in CO2[tex]= (12/44) (20.31)[/tex] grams [tex]= 5.54[/tex] gram
Mass of hydrogen in H2O [tex]= (2/18)(4.26)[/tex] grams [tex]= 0.46[/tex] gram
We will calculate the % of C and H in the sample
% C [tex]= (5.54/6) * 100 = 92[/tex]%
% H [tex]= (0.46/6)*100 = 7.7[/tex]%
Number of mole of C [tex]= 92/12 = 7.69[/tex]
Number of mole of H [tex]= 7.67/1 = 7.67[/tex]
Fractional share of C [tex]= 7.69/7.67 = 1[/tex]
Fractional share of H [tex]= 7.67/7.67 = 1[/tex]
Empirical Formula = CH
Empirical Mass [tex]= 12+1 = 13[/tex]
Molecular mass [tex]= 26[/tex]
Molecular Formula – CHn
N [tex]= 26/13 = 2[/tex]
Molecular Formula = C2H2
A 6.40 g sample of a compound is burned to produce 8.37 g CO_2, 2.75 g H_2O, 1.06 g N_2, and 1.23 g SO_2. What is the empirical formula of the compound? Give your answer in the form C#H#N#O#S# where the number following the element’s symbol corresponds to the subscript in the formula. (Don’t include a 1 subscript explicitly).
The empirical formula :
C₁₀H₁₆N₄SO₇
Further explanationGiven
6.4 g sample
Required
The empirical formula
Solution
mass C :
= 12/44 x 8.37 g
= 2.28
mass H :
= 2/18 x 2.75 g
= 0.305
mass N = 1.06
mass S :
= 32/64 x 1.23
= 0.615
mass O = 6.4 - (2.28+0.305+1.06+0.615) = 2.14 g
Mol ratio :
= C : H : N : S : O
= 2.28/12 : 0.305/1 : 1.06/14 : 0.615/32 : 2.14/16
= 0.19 : 0.305 : 0.076 : 0.019 : 0.133 divided by 0.019
= 10 : 16 : 4 : 1 : 7
The empirical formula :
C₁₀H₁₆N₄SO₇
which of the following describes all of the types of water found in the hydrosphere
Answer: all of the water on the Earth
Explanation:
The hydrosphere is made up of all the water that we have on Earth. Included in the hydrosphere are the water that we have underground, those in the Earth's surface, and those that we have in the air.
On Earth, we can find water in the seas, lakes, oceans, streams, rivers etc. Water also comes in form of rain as well.
As the temperature of a substance increases, the average___________ energy of the particles also increases, and movement overcomes forces of ________ more easily. As temperature decreases particles move more slowly and the_________ forces between particles dominate.
Answer:
Kinetic; attraction; attraction.
Explanation:
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.
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
Hence, as the temperature of a substance increases, the average kinetic energy of the particles also increases, and movement overcomes forces of attraction more easily. As temperature decreases particles move more slowly and the attraction-forces between particles dominate.
In conclusion, when a substance or an object is heated, a phase change starts to occur only when the average kinetic energy of its particles is great enough to overcome the force of attraction between its particles.
After a big game, you put your water bottle inside the refrigerator. The next
day you see that your water bottle has become dented. Which statement
best describes what happened?
A.
Heat molecules left the water bottle.
B.
Some air molecules were broken down.
C.
The air particles slowed down and got closer together.
D.
Some of the air molecules escaped the water bottle.
Mostly and for what I would say is A
The gases can undergo compression when subjected to lower temperatures and pressure. The water bottle becomes dented as the collision slowed down and got closer to each other. Thus, option C is correct.
What is freezing?Freezing has been the physical process that is involved in changing the states of matter from liquid to solids. This results in a decrease in the entropy of the water which decreases the heat and randomness of the particles.
As the temperature decreases the collision and the kinetic energy of the particles decreases. This results in the loss of entropy and makes the molecules or the particles show a higher force of attraction leading to close packing. The space becomes dense and tightly packed.
As the particle becomes closely packed it dents the water bottle at low temperature as now it has its own shape (solids) unlike the liquids. The lower temperature converts the liquids into solids.
Therefore, as the water freezes the bottle experiences a dent as ice is formed from liquids by freezing.
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The circuit below is powered by a 20-volt battery. What current is flowing through the on/off switch (when it is on, as shown)?
Answer:
The answer is "0.38 A".
Explanation:
Please find the missing image file in the attachment.
In the given image let:
[tex]R_{12} =R_1+R_2=16 \ \Omega \\\\R_{34} =R_3+R_4=20 \ \Omega \\[/tex]
[tex]R_P=\frac{R_{12} \cdot R_{34}}{R_{12} +R_{34}}[/tex]
[tex]= \frac{16 \cdot 20 }{16 +20}\\\\= \frac{320 }{36}\\\\= \frac{80 }{9}\\\\= 8.88 \ \Omega[/tex]
similarly,
[tex]R_{eq} =R_p+R_5+R_6\\\\[/tex]
[tex]=8.88+24+20\\\\=52.89 \ \Omega \\\\[/tex]
calculating the current value through a switch:
[tex]\to I=\frac{V}{R_{eq}} = \frac{20 \ v}{52.89 \Omega }=0.38\ A[/tex]
Answer:
D. 0.38 amperes
Explanation:
Got it correct on Gizmos
Gizmos explanation: This compound circuit contains two parallel branches connected in series to 2 more resistors. Each parallel branch contains 2 resistors in series. The resistance of the first branch is 5+11=16 ohms, and the resistance of the second branch is 20 ohms. Using the equivalent resistance formula, the resistance of this section is
1R=116+120=580+480=980
So R is 809, or 8.89 ohms. This is connected in series to a 24-ohm and a 20-ohm resistor, for a total resistance of 52.89 ohms. The battery voltage is 20 volts, so by Ohm's law
I=VR
I=2052.89=0.38amperes
What process forms an image in a mirror? Choices: A. absorbing light B. Reflecting light C. Refracting light D. Transmitting light
Answer
Using the law of reflection—the angle of reflection equals the angle of incidence—we can see that the image and object are the same distance from the mirror. This is a virtual image, since it cannot be projected—the rays only appear to originate from a common point behind the mirror.
Explanation:
Hope this helps someone
1. How do organisms maintain homeostasis?
Answer:
Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them.
Convert
31.82 grams of ca(oh)2 to moles
3.2 moles of K2SO3 to grams
7.25x10^23 formula units of hcl to moles
46.6L of Cl2 gas to moles at STP
Answer:
0.43 moles Ca(OH)₂506.4 grams K₂SO₃1.20 moles HCl2.080 moles Cl₂Explanation:
-We convert Ca(OH)₂ grams to moles using its molar mass:
31.82 g ÷ 74.093 g/mol = 0.43 mol-We convert K₂SO₃ moles to grams using its molar mass:
3.2 mol * 158.26 g/mol = 506.4 g-One formula unit of HCl is HCl. We convert molecules to moles using Avogadro's number:
7.25x10²³ molecules ÷ 6.023x10²³mol/molecules = 1.20 mol-At STP, one mol of any gas occupies 22.4 L:
46.6 L * 1 mol / 22.4 L = 2.080 molSet Grouper to 70%. How do you think this level of fishing will affect the populations of the other fish in the simulated reef? Explain your reasoning.
Answer:
Greatly affect.
Explanation:
This level of fishing will greatly affect the populations of the other fish in the simulated reef because overfishing disturbs the equilibrium in the marine ecosystem. One fish is a food of another fish or the big fish act as a controller which controls the population of other small fishes and in that way the ecosystem is present in equilibrium state so overfishing will greatly affect the marine ecosystem.
[10 pts]Iron and vanadium both have the BCC crystal structure and V forms a substitutional solid solution in Fe for concentrations up to approximately 20 wt.% V at room temperature. Determine the concentration in weight percent of V that must be added to iron to yield a unit cell edge length of 0.289 nm.
Answer:
The answer is below
Explanation:
The unit cell edge length (a) = 0.298 nm = 0.289 * 10⁻⁷ cm
The unit volume (V) = a³ = (0.289 * 10⁻⁷ cm)³ = 24 * 10⁻²⁴ cm³
There are 2 atoms per cell, hence N = 2. Also, [tex]n_a=avogadro\ constant=6.02*10^{23}\ mol^{-1}[/tex]
[tex]atomic\ weight\ of\ iron(A_f)=55.85,atomic\ weight\ of\ vanadium(A_V)=50.94,[/tex]
[tex]density\ of\ iron(\rho_f)=7.87,density\ of\ vanadium(\rho_v)=6.1.\\\\V=\frac{nA_{av}}{n_a\rho_{av}} \\\\A_{av}=\frac{100}{C_v/A_v+C_f/A_f} \\\\\rho_{av}=\frac{100}{C_v/\rho_v+C_f/\rho_f} \\\\C_v=concentration\ of\ vanadium,C_f=concentration\ of\ iron.\\\\V=\frac{nA_{av}}{n_a\rho_{av}}=\frac{n*\frac{100}{C_v/A_v+C_f/A_f}}{n_a*\frac{100}{C_v/\rho_v+C_f/\rho_f}}\\\\[/tex]
[tex]24*10^{-24}=\frac{2*\frac{100}{C_v/50.94+C_f/55.85}}{6.02*10^{23}*\frac{100}{C_v/6.1+C_f/7.87}}\\\\7.2=\frac{C_v/6.1+C_f/7.87}{C_v/50.94+C_f/55.85}\ \ \ (1) \\\\Also:\\\\C_v+C_f=100\%\ \ \ (2)\\\\\\solving\ equation\ 1\ and\ 2\ simultaneously\ gives:\\\\C_v=10\% \ and\ C_f=90\%\\\\[/tex]
ANSWER QUICK !!!
How many grams of hydrogen gas will be produced if you start with 15.0 grams of zinc and an excess amount of HCI?
balanced equation:
Zn + 2HCI = ZnCl2 + H2
Answer:
0.48g
Explanation:
Given parameters:
Mass of zinc = 15g
Unknown:
Mass of hydrogen gas = ?
Solution:
To solve this problem, we need to state the balanced reaction expression first;
Zn + 2HCl → ZnCl₂ + H₂
Find the number of moles of Zn;
Number of moles = [tex]\frac{mass}{molar mass}[/tex] = [tex]\frac{15}{63.4}[/tex] = 0.24mol
From the balanced reaction expression;
1 mole of Zn will produce 1 mole of H₂
0.24mole of Zn will produce 0.24mole of hydrogen gas
Mass of hydrogen gas = number of moles x molar mass
= 0.24 x (2 x 1)
= 0.48g
The balanced equation for the production of sugars by photosynthesis is shown below.
This equation demonstrates the law of conservation of mass because
A.
there are more oxygen atoms on the right side of the equation than on the left.
B.
there is the same number of compounds on the right side of the equation as the left.
C.
there is the same number of each type of atom on the right side of the equation as the left.
D.
the sugar molecule on the right has the same mass as the carbon dioxide molecules on the left.
Answer:
Black
Explanation:
Answer:
the answer is
-there is the same number of each type of atom on the right side of the equation as the left.
Explanation:
i have study island too :')
Which of the following contains a polyatomic ion?
sodium iodide
carbon monoxide
Iron II oxide
ammonium chloride
Answer:
i think its oxide not too sure
Answer:
Its should be ammonium chloride.
A picture to help you with another question like this
In the Energy and Specific Heat lab, what temperature should be recorded as the final temperature of the water when measuring the food sample?
A. The temperature of the water when the food sample is first lit
B. The temperature of the water when the food sample has finished burning completely.
C. The highest temperature the water reaches as the sample burns
D. The temperature of the water after the food sample ash has been removed
Answer:
B. The temperature of the water when the food sample has finished burning completely.
Explanation:
Heat or thermal energy is a form of energy that transfers from one object to another due to a temperature difference between the objects. The units for heat are joules or calories.
Calorimetry is the measurement of heat energy released or absorbed in a chemical reaction. A calorimeter is used in calorimetry. The calorimeter operates on the Law of Conservation of Energy which states that energy is never created or destroyed but is transformed from one form to another or between objects.
In food calorimetry, the energy released when food is burned is measured by recording the rise in temperature of water in a calorimeter when a given mass of a food sample is burned completely.
Energy can be calculated using the formula: Q = mc ∆T
where Q = the energy in joules or calories, m = the mass in grams, c = specific heat and ∆T = the change in temperature (final temperature - initial temperature).
The temperature of the water when the food sample has finished burning completely is taken as the final temperature of the water. The sample is allowed to smolder for sometime before recording the final water temperature. This is because the water temperature will continue to rise after the flame has gone out.
Dolphins have the same arm structure as wolves. What type of evidence for evolution does this represent?
A. DNA
B. vestigial structures
C.homologous structures
D. embryology
1. Consider Reactions 3 and 14 studied in this lab. Write the balanced molecular equation (identical to what you completed in the previous section), the complete ionic equation and the net ionic equation for these reactions. Include all physical states, and circle the spectator ions in the complete ionic equations.
Reaction 3: Aqueous sodium phosphate + aqueous copper(II) sulfate
Balanced Molecular Equation
(from page 1): Complete
Ionic Equation:
Net Ionic Equation:
Reaction 14: Aqueous iron(III) chloride + aqueous ammonium hydroxide
Balanced Molecular Equation
(from page 3): Complete
Ionic Equation:
Net Ionic Equation:
2. Predict the products for the following single and double displacement reactions, and write balanced molecular equations including physical states) for each of them. If you predict that no reaction will occur, write "NR", followed by a brief explanation.
A. Aluminum metal + aqueous silver acetate
B. Aqueous zinc nitrate + aqueous lithium chloride
C. Hydrobromic acid + solid magnesium sulfite
D. Aqueous rubidium hydroxide + perchloric acid
E. Tin metal + phosphoric acid
F. Aqueous lithium chromate + aqueous gold(111) iodide
Answer:
See explanation
Explanation:
For reaction 3;
Molecular equation
2Na3PO4(aq) + 3CuSO4(aq) -----> 3Na2SO4(aq) + Cu3(PO4)2(s)
Complete ionic equation;
6Na^+(aq) + 2PO4^3-(aq) + 3Cu^2+(aq) + 3SO4^2-(aq) ------> 6Na^+(aq) + 3SO4^2-(aq) + Cu3(PO4)2(s)
Net ionic equation;
3Cu^2+(aq) + 2PO4^3-(aq) -----> Cu3(PO4)2(s)
Reaction 14
Molecular equation
2FeCl3(aq) + 6NH4OH(aq) ------>2Fe(OH)3(s) + 6NH4Cl
Complete ionic equation:
2Fe^2+(aq) + 6Cl^-(aq) + 6NH4^+(aq) + 6OH^-(aq) -----> 2Fe(OH)3(s) + 6NH4^+(aq) + 6Cl^-(aq)
Net ionic equation;
2Fe^2+(aq) + 6OH^-(aq) -----> 2Fe(OH)3(s)
2.
Al(s) + 3Ag(CH3COO)(aq) ----->Al(CH3COO)3(aq) + 3Ag(s)
Zn(NO3)2(aq) +2LiCl(aq) ------> 2LiNO3(aq) + ZnCl2(aq)
2HBr(aq) + MgSO3(s) ------>MgBr2(aq) + H2O(l) + SO2(g)
RbOH(aq) + HClO4(aq) -----> RbClO4(aq) + H2O(l)
3Sn(s) + 4H3PO4(aq)----->Sn3(PO4)4(aq) + 6H2(g)
3Li2CrO4(aq) + 2AuI3(aq) -------> 6LiI(aq) + Au2(CrO4)3(s)
Draw the kinetic and thermodynamic addition products formed when one equivalent of HBr reacts with the diene .
Answer:
See explanation and images attached
Explanation:
The addition of HBr to the diene could yield either a kinetic or thermodynamic product. The kinetic product is formed faster while the thermodynamic product is more stable and formed at equilibrium.
Recall that the alkene that is surrounded by more alkyl groups is more stable. Also, the carbocation undergoes rearrangement to form a more stable carbocation intermediate that ultimately leads to the formation of the thermodynamic (1,4) product which predominates.
The structures of the two products are shown in the image attached to this answer.
Which statement about Niels Bohr's atomic model is true?
O Higher orbits have lower energies.
O Each orbit has a specific energy level.
O Electrons can exist in any energy level.
O Orbits close to the nucleus have no energy.
Answer:
O Each orbit has a specific energy level.
Explanation:
Neils Bohr put forward his own model of the atom based on the quantum mechanics originally developed by Planck.
He assumed the Rutherford's model and suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus.
The orbits/energy level are the permissible through which the electrons can move through.
His concept is based the concept that the electron can move round the nucleus in certain permissible orbitss
