please answer Look at this image of a galaxy. Which type of galaxy is shown? A. elliptical B. irregular. C. normal spiral or D. barred spiral

Answer:

rust

Explanation:

Answer:

5.25yr

Explanation:

I think so

Answer:

When substances do not mix thoroughly and evenly (like sand and gravel), the mixture is said to be heterogeneous. A heterogeneous mixture consists of visibly different substances. Another example of a mixture is salt dissolved in water.

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Answer:

The objects should be far apart. There must be air circulation. The objects need to be touching. Solar energy is required.

Explanation:

Answer:

Synthesis

The first reported synthesis of selenium tetrafluoride was by Paul Lebeau in 1907, who treated selenium with fluorine:[1]

Se + 2 F2 → SeF4

A synthesis involving more easily handled reagents entails the fluorination of selenium dioxide with sulfur tetrafluoride:[2]

SF4 + SeO2 → SeF4 + SO2

An intermediate in this reaction is seleninyl fluoride (SeOF2).

Other methods of preparation include fluorinating elemental selenium with chlorine trifluoride:

3 Se + 4 ClF3 → 3 SeF4 + 2 Cl2

Structure and bonding

Selenium in SeF4 has an oxidation state of +4. Its shape in the gaseous phase is similar to that of SF4, having a see-saw shape. VSEPR theory predicts a pseudo-trigonal pyramidal disposition of the five electron pairs around the selenium atom. The axial Se-F bonds are 177 pm with an F-Se-F bond angle of 169.2°. The two other fluorine atoms are attached by shorter bonds (168 pm), with an F-Se-F bond angle of 100.6°. In solution at low concentrations this monomeric structure predominates, but at higher concentrations evidence suggests weak association between SeF4 molecules leading to a distorted octahedral coordination around the selenium atom. In the solid the selenium center also has a distorted octahedral environment.

Reactions

In HF, SeF4 behaves as a weak base, weaker than sulfur tetrafluoride, SF4 (Kb= 2 X 10−2):

SeF4 + HF → SeF3+ + HF2−; (Kb = 4 X 10−4)

Ionic adducts containing the SeF3+ cation are formed with SbF5, AsF5, NbF5, TaF5, and BF3.[3] With caesium fluoride, CsF, the SeF5− anion is formed, which has a square pyramidal structure similar to the isoelectronic chlorine pentafluoride, ClF5 and bromine pentafluoride, BrF5.[4] With 1,1,3,3,5,5-hexamethylpiperidinium fluoride or 1,2-dimethylpropyltrimethylammonium fluoride, the SeF62− anion is formed. This has a distorted octahedral shape which contrasts to the regular octahedral shape of the analogous SeCl62−. [5]

Explanation:

Answer:

If it took the motorcycle 2 hours to cover 20km, then the average speed is 10km per hour.

Explanation:

Speed is equal to distance over time. So 20km divided by 2 hours is 10 km per hour.

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Answer:

96.56063 km/h

Explanation:

1. C

2. D (I’m not entirely sure)

3.energy can neither be created nor destroyed, only change forms.

4. C

5. A

6. C

I’ve researched and tried to answer these questions correctly.

Answer:

1.c

2.a

3.created or destroyed

4.c

5.a

6.c

Explanation:

thanks me later

Answer:

3. x 10⁸m/s

Explanation:

Given parameters:

Frequency of wave  = 7.8 x 10⁶Hz

Unknown:

Speed of the wave = ?

Solution:

All electromagnetic radiation has  a speed of 3. x 10⁸m/s in free space.

No matter the frequency and wavelength, they all have the same speed which is the same as the speed of light.

The speed of electromagnetic wave that has a frequency of [tex]7.8 * 10^{6}[/tex] Hz is [tex]3 * 10^{8}[/tex] m/s.

Electromagnetic waves:

Higher-frequency electromagnetic waves have less energy. All electromagnetic waves travel across space at the speed of light which is  [tex]3 * 10^{8}[/tex] m/s.

As we know that,

Speed=frequency x wavelength,

It follows that the wavelength will also not change. So the direction, speed, frequency and wavelength of any electromagnetic wave are constant and these properties will not change after emission from a source.

Thus, speed of an electromagnetic wave is fixed and does not change on varying frequencies which is [tex]3 * 10^{8}[/tex] m/s.

OR

The waves travel at the same speed, but the observed frequency depends on any relative motion between the observer and source.

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Answer:

what? what do you mean?

Answer:

?

Explanation:

Answer:

electric field or magnetic field both are same

Explanation:

in an electromagnet the movement of electrons in a wire creates the magnetic field.an electromagnet and the permanent magnet both the magnet have the magnetic fields that can attract the same kinds of materials.

Answer:

i think it's D

Explanation:

sorry if its wrong

The issue that is associated with nuclear power is the biggest source of debate is what to do with radioactive waste. The correct option is D

Nuclear power is the power that is generated by combining or breaking nuclear atoms. There are two processes for generating nuclear power. They are nuclear fission, in which the breaking of big nuclei happens. Nuclear fusion, in which two nuclei join together to form a big nucleus.

Nuclear waste is the radiation generated from nuclear fission and fusion. This waste is very harmful to nature and animals. It can cause many deformities in humans and genetic disorders.

Nuclear waste is highly challenging, and its disposal is very hard, deep geological disposal is the only option.

Thus, the correct option is D, what to do with radioactive waste.

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Answer:

0.75M Fe²⁺

Explanation:

First, we need to balance the redox reaction in acidic medium. Then, we can obtain moles of KMnO4 and with the reaction moles and molarity of the Fe²⁺ solution:

Redox Balance:

Fe²⁺ → Fe³⁺ + 1e⁻

5e⁻ + 8H⁺ + MnO₄⁻ → Mn²⁺ + 4H₂O

___________________________

5Fe²⁺ + 5e⁻ + 8H⁺ + MnO₄⁻ → 5Fe³⁺ + 5e⁻ + Mn²⁺ + 4H₂O

Moles of KMnO₄:

70.0mL = 0.0700L * (0.150mol / L) = 0.0105 moles KMnO₄

Moles and molarity Fe²⁺:

0.0105 moles KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.0525 moles Fe²⁺

In 70.0mL = 0.0700L:

0.0525 moles Fe²⁺ / 0.0700L =

Answer:

it's a symbiotic mutual relationship

Explanation:

Greenish-brown algae lives on the crab's back, helping the crabs blend in with their enviroment, which makes them less noticeable to predators. the algae provided with a good place to live while the crab receives camouflage.

Answer:

Mutualism

Explanation:

Mutualism; One organism live in, on, or near another, and both gain something they need for survival. Both organisms are heled.

Answer:

Oxygen supports combustion so a good method of testing for oxygen is to take a glowing splint and place it in a sample of gas, if it re-ignites the gas is oxygen. This is a simple but effective test for oxygen.

Explanation:

Answer: The 'mass of the object' directly affects kinetic energy

Explanation:

Answer:

9vguvvg9uvu

Explanation:

The mass of one mole or 6.02 × 10²³ molecules of water is 18 g/mol. Then, the mass of one molecule of water is 2.99 × 10⁻²³ g/molecule.

The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to  6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.

Similarly, one mole of a compound contains  6.02 × 10²³ number of molecules. Thus, one mole of water contains these much molecules. The mass of one mole of an element is called its atomic mass. Similarly the mass of one mole of a compound is called its molar mass.

Molar mass of water = 18 g/mol

18 g is the mass of 6.02 × 10²³  molecules of water. Hence, the mass of one molecule of water is;

= 18 g/mol/6.02 × 10²³ molecule/mol

= 2.99 × 10⁻²³ g/molecule

Therefore, the mass of one molecule of  H₂O  is 2.99 × 10⁻²³ g/molecule.

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Answer:

27.19 cm.

Explanation:

From the question given above, the following data were obtained:

Height (h) of cylinder = 6461.76 cm

Volume (V) of cylinder = 15000000 cm³

P1 (π) = 3.14

Radius (r) =.?

Thus, we can obtain the radius of the cylinder water tank by using the following formula as illustrated below:

V = πr²h

15000000 = 3.14 × r² × 6461.76

15000000 = 3.14 × 6461.76 × r²

Divide both side by 3.14 × 6461.76

r² = 15000000 / (3.14 × 6461.76)

Take the square root of both side

r = √[15000000 / (3.14 × 6461.76)]

r = 27.19 cm

Thus, the radius of the cylinder water tank is 27.19 cm.

Answer:

3,717,813

Im not sure, I will get back to you soon

Answer:

Scale is the right answer

Explanation:

The  scale is a sentence that relates distance on the map to distance on Earth

The scale of a map represents the relationship between the distances on the map and the actual distances on Earth.

A map is a symbolic representation of selected features of a location, typically drawn on a flat surface. Maps present information about the world in a straightforward, visual format. They teach about the world by displaying country sizes and shapes, feature locations, and distances between locations.

The ratio of a distance on Earth to the same distance on a map is known as map scale. On maps, three types of scales are commonly used: written or verbal scales, graphic scales, and fractional scales.

The map scale is the relationship between the distance on a map and the actual distance on Earth.

Thus, The scale of a map represents the relationship between the distances on the map and the actual distances on Earth.

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Answer:

The protons are located in the nucleus and have a positive charge

Explanation:

Answer:

The awnser is cerebral palsy

Explanation:

that is a medical condition caused when there is not enough oxygen to the brain at birth

BRAINLIEST PLEASE

Answer: density, Omass, radiation, pressure because  Radiation pressure is the mechanical pressure exerted upon any surface . Small bodies are more affected than large ones because of their lower mass relative to their surface area formed by the radiation pressure of the young stars reduces the cluster mass enough to allow rapid dispersal.

Explanation: I Hope that helped!!!