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Answer:

number 29 is D

Explanation: When the moon orbits the earth some of the light reflects off the moon, making it visible on the Earth.

I dont know how to answer 28 fully, is there a picture?

Answer:

The average kinetic energy increases, and the particles collide more frequently.

Explanation:

Answer:

Sn has a different charge in each of the compounds.

+2, +4 charges, respectively.  

Explanation:

SnO has subscripts of 1, which means it takes only one of each element to make the compound.

We know that oxygen's charge is -2 from the periodic table.

In order for the compound to be neutrally charged,

Sn + O = 0

Sn - 2 = 0.

So, Sn has a +2 charge.

Likewise with the second compound, we know O has a -2 charge.

Sn + 2*(-2) = 0

Sn - 4 = 0

Sn = +4

+2 and +4 are different charges on the Sn cation.  

Answer:

activity series is a list of substances ranked in order of relative reactivity.

For example, magnesium metal can displace hydrogen ions from solution. So magnesium is more reactive than hydrogen:

Mg(s) + 2H⁺(aq) → H₂(g) + Mg²⁺(aq)

Zinc metal can also displace hydrogen ions from solution:

Zn(s) + 2H⁺(aq) → H₂(g) + Zn²⁺(aq)

so zinc is also more active than hydrogen.

But magnesium metal can displace zinc ions from solution:

Mg(s) + Zn²⁺(aq) → Zn(s) + Mg²⁺(aq)

so magnesium is more active than zinc.

The activity series including these elements would be Mg > Zn > H.

Chemists have built up a complete activity series in a similar way.

The most active metals are at the top of the table; the least active are at the bottom.

Any metal that is higher in the series will displace a metal that is below it in a

The knowledge of the activity series in choosing which metal to build things with because; it provides a basis for determining which metal ion is able to displace the other upon chemical interaction.

The choice of building material is a very important design consideration.

This variation is carefully quantified by the position of metals on the activity series.

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Answer:

Covalent bond between identical atoms

Covalent bonds occur between identical atoms or between different atoms whose difference in electronegativity is insufficient to allow transfer of electrons to form ions. ... The two hydrogen atoms are attracted to the same pair of electrons in the covalent bond.

Answer:9.38 x 10^−3 m

Explanation:

Answer: 9.38 x 10^−3 m

Explanation:

Answer:ultraviolet rays

Explanation:

Explanation:

Ethanol-filled thermometers are used in preference to mercury for meteorological measurements of minimum temperatures and can be used down to −70 °C (−94 °F). The physical limitation of the ability of a thermometer to measure low temperature is the freezing point of the liquid used.

Answer:

Explanation:

Answer:

1/8

Explanation:

[tex] \frac{1}{ {2}^{3} } = \frac{1}{8} [/tex]

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Answer:

ACID RAIN

Explanation:

duh

Answer:

Yes.

Explanation:

Answer:

=0=0==00=0=0=

Explanation:

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Answer:

129 units cubed

Explanation:

There are ten spaces between 120 and 130, so we can infer that each line represents a change in volume of 1 unit. The volume of the substance in the graduated cylinder looks like it's 1 under 130, so its volume is 129 units.

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Answer:

The convection zone :)

Answer:

a hydrogen ion will have more or fewer electrons than a standard hydrogen atom.

Explanation:

ions are atoms that have lost or gained elections. this applies to ions in general.

Answer:

Lithium has 1 valence electron, Sulfur has 6

A is oxidized, B is reduced

A is reducing agent, B is oxidizing agent

Explanation:

when an atom loses electrons, it is oxidized

when an atom gains electrons, it is reduced (almost think of when you add a negative number to a positive number, the positive number gets smaller or is reduced)

Answer:

There are 10 neutrons

Explanation:

Because the atomic number is 8 and the isotope number is 18 (which is the collective protons and neutrons), we can do

18-8=10

Answer:

10

Explanation:

8 proton because it is oxygen

10 neutron because 18-8

Answer:

is not completely ionized in water

The ethanoic acid (acetic acid) is considered as a weak acid because it does not releases all of its hydrogen in water, rather it dissociates partially and establishes an equilibrium with its conjugate base.

Answer:

Density 0.78945 g/cm3 (at 20 °C)

Melting point −114.14 ± 0.03 °C (−173.45 ± 0.05 °F; 159.01 ± 0.03 K)

Boiling point 78.23 ± 0.09 °C (172.81 ± 0.16 °F; 351.38 ± 0.09 K)

Solubility in water Miscible

Explanation:

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Answer: the answer should be A the first one

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Answer:

see this

Explanation:

Answer: 57.C

Explanation: simple subtraction

There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.

Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution.

Solute is the substance which is in small amount in a solution. Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.

Therefore, Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.

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Answer:

strong winds come from the energy of a hurricane

The energy of a hurricane come from strong wind. The Taino Native American term hurricane, which translates to "bad spirit of the wind," is where the word hurricane originates.

A tropical storm that has sustained winds of 74 mph or greater is referred regarded as a hurricane. A storm's eye typically measures 20 to 30 miles in width and can reach distances of 400 miles. Storms can be dangerous because of their torrential downpours, strong gusts, and storm surges.

When warm, humid air begins to rise over water, hurricanes emerge. Cooler air replaces the rising air. Large clouds and thunderstorms continue to grow as a result of this process. Thanks to the earth's Coriolis Effect, these thunderstorms are still expanding and starting to rotate.

Thus, option B is correct.

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Answer:

The most common injury caused by working with machinery are cuts and burns.

Explanation:

Cuts and burns are the  most common injury caused by working with machines unsafely.

Any physiological harm to living tissue brought on by acute physical stress is referred to as an injury. An injury can be brought on by a blunt trauma, a piercing trauma, burning, exposure to chemicals, asphyxiation, or overexertion, and it can also happen accidentally. Any area of the body can become injured, and each injury has a unique set of symptoms.

Major injuries are normally treated by a medical practitioner, and the type of treatment depends considerably on the injury. The most frequent reason for accidental human injury or injury-related death is traffic crashes. Chronic conditions are different from injuries. Cuts and burns are the  most common injury caused by working with machines unsafely.

Therefore,  Cuts and burns are the  most common injury caused by working with machines unsafely.

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Answer:

True

Explanation:

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points.

Answer:

Valency of nitrogen in the given compounds:

N₂O₃ = +3

N₂O₅ = +5

NO = +2

-TheUnknownScientist 72

Answer:

Because people can now see microscopic items

Explanation:

People can now see the cells because they are so small we cant see them with the enhanced microscope we can see everything that's micro