URGENT  Please I need help answering these two questions ASAP

Answer:

NaCl (common salt) is solid in state and solid ions or compounds don't conduct electricity. It needs to be either melted, molten or dissolved in a solution (i.e. water) first.

Explanation:

Answer:

The term ‘ozone hole’ refers to the depletion of the protective ozone layer in the upper atmosphere (stratosphere) over Earth's polar regions. People, plants, and animals living under the ozone hole are harmed by the solar radiation now reaching the Earth's surface—where it causes health problems, from eye damage to skin cancer.

The Theory of Continental Drift says that the continents were once joined together and are drifting apart, Alfred Wegener is given credit for coming up with this theory.

Continental drift is a kind of illusion in which it looks like that continents changes their places over the surface of the earth. The Theory of Continental Drift was given by Alfred Wegener, it is a hypothesis and according to this theory the continents will move with respect to the geological time relative to each other. And due to their movement on the non planar or dynamic geographical base it looks like a drift.

Hence, option (2) is correct i.e. Alfred Wegener gave this theory.

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Answer:

a

Explanation:

Answer:

is Answer of your question.

Thank you ☺️☺️

Explanation:

i guess it's through thousands of research and experiments they conducted

The mass in grams of 4.60 mol of nitrogen is 129g.

Mass of any substance will be calculated by using their moles as:

n = W/M, where

W = required mass

M = molar mass

Given molar mass of nitrogen (N₂) = 28.02 g/mol

Given moles of nitrogen (N₂) = 4.60 mole

On putting these values on the above equation and calculated for W, we get

W = (4.60 mol)(28.02 g/mol)

W = 128.89g = 129g

Hence the required mass is 129g.

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Answer:

D

Explanation:

Answer:

The heat capacity of an object is an amount of energy divided by a temperature change, which has the dimension L2·M·T−2·Θ−1. Therefore, the SI unit J/K is equivalent to kilogram meter squared per second squared per kelvin (kg m2 s−2 K−1 ).

Explanation:

Answer:

Kinetic Energy

Explanation:

The energy an object has due to its motion is called kinetic energy.

Answer:   5.1 x 10^-3 < 0.0057 < 4.9 x 10^-2 < 0.0072 x 10^2 < 5.3 x 10^4 < 57 x 10^3

Because:- 5.3 x 10^4 = 53000

                 57 x 10^3 = 57000

                  4.9 x 10^-2 = 0.049

                 0.0057 = 0.0057

                 5.1 x 10^-3 = 0.0051

                 0.0072 x 10^2 = 0.72

___________________________

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Answer:" For example, when hydrogen gas, H2(g), is burned in the presence of gaseous oxygen, O2(g), a new substance, liquid water, H2O(l ), forms. The covalent bonds within the H2 molecules and O2 molecules break, and new covalent bonds form between oxygen atoms and hydrogen atoms (Figure 7.1)."

Explanation:

Answer:

22 626 000 J. = 22 626 kJ. 4. If 9000 J of heat are absorbed by 800 g of water at 5.0 o. C, what maximum temperature will the water attain? Q = mc ∆T.

Explanation:

The final temperature can be calculated using the calorimetric equation. Here, the final temperature of water is 27.71 °C.

The calorimetric equation connecting the heat energy absorbed or released q by a system with the mass m, temperature difference ΔT and the specific heat capacity c as follows:

q = m c ΔT

The specific heat capacity of water = 4.15 J/ °C g.

given that heat energy absorbed q = 9000 J

mass = 800 g

initial temperature = 25 °C.

Then,

9000 J = 4.15 J/ °C g. × 800 g (25 °C + T)

then T = [ 9000 J/  4.15 J/ °C g. × 800 g ] + 25 °C = 27.71  °C.

Therefore, the final temperature of water is 27.71  °C.

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Answer:

[tex]V=3850.1769\;L[/tex]

Explanation:

Gas law is the mathematical relationship among pressure,volume, temperature, and the number of moles of a gas. It is the equation of state for an ideal gas. Which is because the state of a gas can be known by it pressure, volume, temperature, and number of moles.
Look below which "R" is a constant

[tex]PV=nRT[/tex]

[tex]n=8.47kg\times(\frac{1000g}{1kg})\times(\frac{1mol}{64.066g})[/tex]

[tex]n=132.2074\;mol[/tex]

[tex]V=\frac{nRT}{P}[/tex]

[tex]V=\frac{(132.2074\\;mol\times(8.314\frac{L\cdotkPa}{mol\cdotk)}\times(40+273.15)k}{89.4\;kPa}[/tex]

or (3.85 x 10^3 L)

[tex]V=3850.1769\;L[/tex]

~Lenvy~

Answer:

Cuz they are reversible changes that do not change matter's chemical makeup or chemical properties. Processes involved in changes of state include melting, freezing, sublimation, deposition, condensation, and evaporation.

Explanation:

Answer:

[Ar] 4s²

Explanation:

Answer:

A. Logic

Explanation:

Answer:

Logic. When interepreting scientific information you have to always use logic

Explanation:

Answer: Gravity

Explanation: The answer is gravity: an invisible force that pulls objects toward each other. ... So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body.

Answer:

Genetics is the scientific study of genes and heredity.

Explanation:

The last one is endothermic, as you can notice we are using up energy (absorbing energy) in order for the reaction to occur.

Whereas the other ones release energy, as they are considered exothermic.

Stoichiometry can be used to determine the molality, molarity and volume of substances in a reaction.

The term concentration refers to the amount of substance present in a solution.

1. Number of moles of NaCl = 142.8 g /52 gg/mol = 2.7 moles

Molarity =  2.7 moles/  2.3 L = 1.17 M

2. 67.5 % of magnesium chloride implies 67.5 g of MgCl2 in 100 g of solution.

Number of moles of MgCl2 = 67.5 g/95 g/mol = 0.7 moles

molality = 0.7 moles/32.5 * 10^-3 = 21.5 m

3. Number of moles of the sugar = 62.5 g/342 g/mol = 0.18 moles

Number of moles of water = 250 g/18 g/mol = 13.9 moles

Since 1 g of water = 1 cm^3 water

Molarity =  0.18 moles/250  * 10^-3 = 0.72M

Molality =  0.18 moles/250  * 10^-3 = 0.72m

Mole fraction of sugar = 0.18/(0.18 + 13.9 ) = 0.01

Mole fraction of water =  13.9 /(0.18 + 13.9 ) = 0.99

4. A 48% solution of HCl contains 48 g of HCl in 100 g of water.

Number of moles of HCl = 48 g/36.5 g/mol = 1.3 moles

Number of moles of water = 52g/18 g/mol = 2.9 moles

Mole fraction of HCl = 1.3/(1.3 + 2.9) = 0.31

Mole fraction of water = 2.9/(1.3 + 2.9) =0.69

5. 1.75 mol  =  0.770 M  * V

V =  1.75 mol/0.770 M

V = 2.27 L

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Answer:

Knowing the units of measurement that correspond with a number can give you so much more information than a digit sitting there by itself. Units can: Help to show another person the exact amount you have.

Explanation:

Answer:

The laboratory equipment is called beaker

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\[/tex]

From the question

mass = 411 g

volume = 384 cm³

We have

[tex]density = \frac{411}{384} \\ = 1.0703125[/tex]

We have the final answer as

Hope this helps you

Answer:

Explanation:

Ionic bonds result from transfer of electrons, whereas covalent bonds are formed by sharing. 2. Ionic bonds are electrostatic in nature, resulting from that attraction of positive and negative ions that result from the electron transfer process; charge separation between covalently bonded atoms is less extreme.

The wavelength : 1.31 m

Waves are vibrations that travel  

There are several parts of the wave namely:  

frequency, period, wavelength and wave velocity  

Frequency (f): the number of waves that occur in one second  

Period (T): The time required to travel one wave  

Wavelength (λ): the distance from one crest to another, or from one trough to another (on transverse waves) and the distance between two consecutive compressions or between two consecutive rarefactions (on longitudinal waves)  

Fast wave propagation (v): the distance traveled by waves per unit of time  

The formula:

 [tex]\tt v=\lambda\times f[/tex]

The speed of a sound wave 345 m, and the frequency = 264 Hz , so

v = 345 m

f = 264 Hz,  

then the wavelength :

[tex]\tt \lambda=\dfrac{v}{f}=\dfrac{345}{264}=\boxed{\bold{1.31~m}}[/tex]

Answer:

a: 157cs = 1.57s

b: 42.7L = 42,700mL

c: 261nm = 0.000261mm

d: 0.0065km = 65dm

e: 642cg = 0.0064km

f: 8.25 x 10^2cg = 8,250,000,000ng

Answer:

a) 1.57

b) 42,700

c) 0.000261

d) 650

e) 0.00642

cant figure out f

Explanation:

According to this question, a substance with a high volatility readily evaporates.

Volatility is the characteristics of a material which describes how readily the material undergo vaporization.

Volatile substances readily change phase from solid or liquid to gases via the process of vaporization.

Therefore, according to this question, a substance with a high volatility readily evaporates.

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C- main sequnce

Regulus A is a binary star consisting of a blue-white main sequence star of spectral type B7V, which is orbited by a star of at least 0.3 solar masses, which is probably a white dwarf. The two stars take approximately 40 days to complete an orbit around their common centre of mass.