which of the following is a pure substance that contains two or more elements?

Answer:

what is your question tell may i can help you

Answer:

decrease as we go down a group I know ionisation energy increases from left to right across the periodic table

Answer:

He put segregationists in charge of federal agencies...

Explanation:

...

Answer:

He placed segregationists in charge of federal agencies.

Explanation:

This problem is providing two reduction-oxidation (redox) reactions in which the oxidized and reduced species can be identified by firstly setting the oxidation number of each element:

Reaction 1: 2K⁺I⁻ + H₂⁺O₂⁻  ⇒2K⁺O⁻²H⁺ + I₂⁰

Reaction 2: Cl₂⁰ + H₂⁰ ⇒ 2H⁺CI⁻

Next, we can see that iodine is being oxidized and oxygen reduced in reaction #1 and chlorine is being reduced and hydrogen oxidized in reaction #2 because the oxidized species increase the oxidation number whereas the reduced ones decrease it.

In such a way, the correct choice is C.

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Answer:

The answer is D. Kinetic energy is the energy of motion.

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Rank the crystal lattice structures in order of decreasing efficiency of space in the structure.

1. Simple cubic

2. Body centered cubic

3. Face centered cubic

4. Hexegonal close packed

Answer:

In general, the magnetic field is strongest close to the wire and weaker farther away. In fact, the magnetic field weakens as 1/r1/r where rr is the distance from the wire. This can change a bit depending on the length and shape of the wire. Far enough away, the magnetic field decays as 1/r21/r2 .

Answer:

Closest to the wire

Explanation:

In general, the magnetic field is strongest close to the wire and weaker farther away. In fact, the magnetic field weakens as where is the distance from the wire. This can change a bit depending on the length and shape of the wire.

The density of the gas is obtained as  0.55 g/L.

We can find the density of the gas using the relation;

PM = dRT

P = pressure of the gas

M = molar mass of the gas

d = density of the gas

R = gas constant

T = temperature

Now;

P = 29.9 kPa

R = 8.314 L·kPa mol·K.

T =  147°C + 273 = 420 K

d = ?

M = 64 g/mol

Substituting values;

d = PM/RT

d =  29.9 kPa ×  64 g/mol/ 8.314 L·kPa mol-1K-1 420 K

d = 1913.6/3491.88

d = 0.55 g/L

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Answer:

Electrons

Explanation:

Because the nucleas is In the middle and the Electrons surround it

Answer:

D

Explanation:

Protons and Neutrons both have a mass of about 1 amu so you add them but electrons have a mass of 0 amu so they are left out.

Answer:

B cells and T cells. The B cells produce antibodies that are used to attack invading bacteria, viruses, and toxins. The T cells destroy the body's own cells that have themselves been taken over by viruses or become cancerous.

Explanation:

Answer:

gasese molecules are always in free state

Answer:

1. H=2, O=1

2. H=4, O=2

3. C=1, O=1

4.

a. reactants C=1, O=2

b. products C=1, O=2

5.

a. reactants H=4, O=2

b. products H=4, O=2

6

a. reactants C=1, O=1, H=4

b. products C=1, O=1, H=4

The question that will best help the student to classify the material is; "is the material malleable or ductile?"

Generally, materials can be classified as metals or non metals. There are properties that are particular to metals and there are properties that are particular to nonmetals and these properties can be used to identify each one of the materials.

The question that will best help the student to classify the material is; "is the material malleable or ductile?" These metallic properties.

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Missing parts;

A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material? A. Is the material malleable or ductile? B. Does the material feel hard to the touch? C. Will the material float in water? D. Does the material feel rough or smooth?

Answer:

Oxygen, heat, and fuel

Explanation:

Oxygen, heat, and fuel are frequently referred to as the "fire triangle." Add in the fourth element, the chemical reaction, and you actually have a fire "tetrahedron." The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.

Considering the rule of three and molar mass of O, the mass of O²⁻ ions in 3 mol of alumina Al₂O₃ is 96 grams.

By multiplying the number of moles by the subscripts next to each atom, you get the amount of each element present in the compound. IIf the same atom appears more than once in the compound, you must add its amounts.

So, in 1 mole of Al₂O₃, you have 2 ions of O²⁻.

Then you can apply the following rule of three: if 1 mole of the compound contains 2 ions of O²⁻, 3 moles of the compound contains how many ions of O²⁻?

[tex]amount of ions of O^{2-} =\frac{3 moles of Al_{2} O_{3} x2 ions of O^{2-}}{1mole of Al_{2} O_{3} }[/tex]

amount of ions of O²⁻= 6 ions

Being the molar mass of O 16 g/mole, this is the amount of mass that a substance contains in one mole, then the mass of O²⁻ can be calculated as:

6 x 16 g/mole= 96 grams

Finally, the mass of O²⁻ ions in 3 mol of alumina Al₂O₃ is 96 grams.

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Answer:

The mixture of cryolite and aluminum oxide has a lower melting point than pure aluminum oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.

Explanation:

Answer:

The presence of drugs or chemicals in an organisms environment can also influence gene expression in the orgains.

Answer:

1 grams Cobalt(II) Sulfate = 0.006451787725861 mole using the molecular weight calculator and the molar mass of CoSO4.

Explanation:

Answer:

From bottom to top, Troposphere, Stratosphere, Mesosphere, Thermosphere, & at the top, Exosphere.

Explanation:

Assuming the surface on which the box moves is frictionless, the rate at which the box accelerate is equal to 0.5 [tex]m/s^2[/tex].

Given the following data:

To determine the rate at which the box accelerate, assuming the surface on which the box moves is frictionless:

Mathematically, Newton's Second Law of Motion is given by the formula;

[tex]Force = mass \times acceleration[/tex]

Making acceleration the subject of formula, we have:

[tex]Acceleration =\frac{Force}{mass}[/tex]

Substituting the given parameters into the formula, we have;

[tex]Acceleration = \frac{25}{50}[/tex]

Acceleration = 0.5 [tex]m/s^2[/tex]

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Answer:

5 significant figures

Explanation:

The zeros as considered when they are in between or after numbers greater than zero.

Ex1: 0.005 = 1 significant figure

Ex2: 0.0050 = 2 significant figure

Ex3: 0.05500= 4 significant figure

Ex4: 5.00 = 1 significant figure

6.5 moles of AgCl can be formed from 6.5 moles of Ag.

STOICHIOMETRY:

According to this question, silver reacts with hydrochloric acid to form silver chloride and hydrogen gas as follows:

2Ag + 2HCl → 2AgCl + H2

Based on this balanced equation, 2 moles of silver (Ag) produces 2 moles of silver chloride (AgCl).

This means that 6.5 moles of Ag will produce (6.5 × 2)/2 = 6.5 moles of AgCl.

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Answer:

option a is the answer

Explanation:

bye bye

Answer:

Solid, liquid, and gas are common states of matter. Because each particle is attached to several others, individual particles cannot move from one location to another, and the solid is rigid. A has a fixed volume but does not have a fixed shape. Liquids take on the shape of the container they are in.

Explanation:

sorry, this is what i think

Answer:

This is a reflector telescope and  in which it captures different wavelengths of light and it hits one mirror, bounces back and hits another and then is shown through the eyepiece. It captures all of the visible spectrum and some areas above and below it. These telescopes are better for seeing big picture and not the fine details in planets surfaces.

Hope this helps!

Explanation:

Answer:

This is a reflector telescope and  in which it captures different wavelengths of light and it hits one mirror, bounces back and hits another and then is shown through the eyepiece. It captures all of the visible spectrum and some areas above and below it. These telescopes are better for seeing big picture and not the fine details in planets surfaces.

Hope this helps!

Explanation:

Answer:

It is strongly recommended that students do NOT wear contacts lenses in the laboratory. Chemical vapors may penetrate the contact lens material and cause the lens to adhere to one's eye, which could be detrimental to the eye. Goggles are not vapor tight and do not completely eliminate this absorption.

Answer: 23.53g

Explanation:

5.2/(2x16) = 0.1625 mol

0.1625 x 2 = 0.325 mol

0.325 x (23 x 2 + 16 x 2) = 78 x 0.325 = 23.53g