Which of the following describes a crystal? *

A homogeneous solid
has a highly ordered microscopic structure
has a geometrically regular form
All of the options describe crystals

Answer:

Speed is the rate of change of position expressed as distance travelled per unit of time .

Explanation:

Answer:

When an organism dies, it is usually destroyed by other forms of life and by weathering processes. On rare occasions some body parts—particularly hard ones such as shells, teeth, or bones—are preserved by being buried in mud or protected in some other way from predators and weather. Eventually, they may become petrified and preserved indefinitely with the rocks in which they are embedded. Methods such as radiometric dating—measuring the amounts of natural radioactive atoms that remain in certain minerals to determine the elapsed time since they were constituted—make it possible to estimate the time period when the rocks, and the fossils associated with them.

Answer:

Pressure will increase by the direct ratio of the volume change. Therefore, since volume changes from 145 to 80, pressure will go up by the ratio change 145÷80 times the original pressure 125 kPa. Sure, you can use the more complicated gas law equation PV = nRT but we are only varying volume so the question boils down to the change in one simple variable.

Putting them together we have: 145÷80 x 125 = 226.5625 or just 226 kPa since the accuracy of the figures and the equation are not great.

Answer:

these metals are stored in kerosene because kerosene contains no water and protects these metals from being exposed to any moisture in the air that would cause these metals to react, potentially violently.

A- the decay of U-238 to Th-234

right on edge 2021

Answer:

A) the decay of U-238 to Th-234

:)

Explanation:

Answer:

geologic time scale

hope this helps

have a good day :)

Explanation:

Answer:

1.06 liters of gas are produced

Explanation:

Our reaction is:

CaCO₃(s) → CaO(s) + CO₂ (g)

This is the decomposition of calcium carbonate.

Ratio is 1:1:1

1 mol of carbonate can decompose to 1 mol of oxide and 1 mol of oxygen.

We convert mass to moles:

4.74 g . 1 mol /100.08g = 0.0474 moles

These are the moles of oxygen produced.

We know that 1 mol of any gas at STP is contained in 22.4L

0.0474 mol . 22.4L /mol = 1.06 L

Answer:

d)1:2

Explanation:

Answer:If we dissolve NaF in water, we get the following equilibrium:

text{F}^-(aq)+text{H}_2text{O}(l) rightleftarrows text{HF}(aq)+text{OH}^-(aq)

The pH of the resulting solution can be determined if the  K_b of the fluoride ion is known.

20.0 g of sodium fluoride is dissolve in enough water to make 500.0 mL of solution. Calculate the pH of the solution. The  K_b of the fluoride ion is 1.4 × 10 −11 .

Step 1: List the known values and plan the problem.

Known

mass NaF = 20.0 g

molar mass NaF = 41.99 g/mol

volume solution = 0.500 L

K_b of F – = 1.4 × 10 −11

Unknown

pH of solution = ?

The molarity of the F − solution can be calculated from the mass, molar mass, and solution volume. Since NaF completely dissociates, the molarity of the NaF is equal to the molarity of the F − ion. An ICE Table (below) can be used to calculate the concentration of OH − produced and then the pH of the solution.

Explanation:

Answer:

not sure if this is 100% correct but this is what i got first question: molarity=mol/L 5g*1mol/58.44g=5/58.44 =0.085558mol 4.8m=0.085558/L L=0.0178

jiujuan avatar

second question: pH = - log [H3O+] pH= -log [4.6*10^-9] = 8.33724216

Explanation:

Answer:

CH2

Explanation:

The empirical formula is the simplest formula of a chemical compound. It shows the ratio in which constituent atoms are combined in the compound.

To obtain the empirical formula, we divide the given mass of each element by the relative atomic mass of that element.

C- 36.0 g/12.0 g         H- 6.0g/1.0g

C- 3                             H-6

Divide through by the lowest ratio;

C-3/3                              H- 6/3

C-1                                  H-2

Hence the empirical formula of the compound is

CH2

Answer:

0.16 J/g℃

Explanation:

We have the following data:

heat = 1,200 J

mass of metal = m = 150 g

change in temperature = ΔT = 50.0℃

The heat absorbed is calculated by using the following equation:

heat = m x Cp x ΔT

So, we introduce the data in the equation to calculate the specific heat of the metal (Cp), as follows:

Cp = heat/(m x ΔT) = (1,200 J)/(150 g x 50.0℃) = 0.16 J/g℃

Answer:

You transfer kinetic energy from you foot to the ball.

Explanation:

Energy cannot be created or destroyed.

Answer:

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Answer:

The particles move very fast and collide into one another, causing them to diffuse, or spread out, until they are evenly distributed throughout the volume of the container. When more gas particles enter a container, there is less space for the particles to spread out, and they become compressed.

Explanation:

Answer: The ratio of the initial volume to final volume for the given gas is 27 to 127 L at constant pressure.

Explanation:

Given: [tex]T_{1} = 27^{o}C[/tex]

[tex]T_{2} = 127^{o}C[/tex]

According to Charle's law, for an ideal gas pressure is directly proportional to the temperature at constant pressure.

So, formula used to calculate the ratio of the initial volume to final volume is as follows.

[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Substitute the values into above formula as follows.

[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}\\\frac{V_{1}}{V_{2}} = \frac{T_{1}}{T_{2}}\\\frac{V_{1}}{V_{2}} = \frac{27}{127}[/tex]

Hence, we can conclude that the ratio of the initial volume to final volume for the given gas is 27 to 127 L at constant pressure.

Answer:

Explanation:

Answer:

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Answer:

No, it is not.

Explanation:

Oil is a non-renewable source of energy. ... Burning oil can pollute the air. Much of our oil has to be imported and it is becoming more and more expensive as reserves reduce and imports increase. Producing electricity from crude oil is expensive compared to other fossil fuels such as coal or gas.

*You Can put this in your own words

Answer:

hydrochloric acid

Explanation:

Zinc oxide will react with hydrochloric acid to form zinc chloride and water.

sulphuric acid

So to make zinc sulphate crystals you add granulated zinc to heated sulphuric acid

Periodic table has been divided into three, one is metal, second is non metal and third metalloid. Therefore,  hydrogen is considered as non metal.

Metals are those elements which is hard, conduct electricity, ductile, lustrous and malleable.

Lets take property

1.Since metals have free electrons that's why they can conduct electricity

2. Since atoms in metals are very closely packed in a definite crystal so Aluminium is solid. It is not brittle that is it can not be broken down easily

3. It does not react with water.

4.It is denser than water hence it sink in water.

Since hydrogen has only 1 electron in its outermost shell, to complete its duet and gain stability, hydrogen has to gain 1 electron just like halogen. So, on this basis hydrogen is considered as non metal.

Therefore,  hydrogen is considered as non metal.

Learn more about the metals, here:

https://brainly.com/question/27859211

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Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

[tex]P_1V_1 = P_2V_2[/tex]

Since we're finding the new volume

[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]

We have

[tex]V_2 = \frac{100 \times 740}{780} = \frac{74000}{780} \\ = 94.8717...[/tex]

We have the final answer as

Hope this helps you

Answer:

λ = 2.94 m (in meters)

λ = 2.94 x 10⁹ nm (in nanometers)

λ = 2.94 x 10¹⁰ A (in angstrom)

Explanation:

The wavelength of the radio station can be given as follows:

[tex]\lambda = \frac{c}{f}\\[/tex]

where,

λ = wavelength = ?

f = frequency = 102 MHz = 1.02 x 10⁸ Hz

c = speed of light = 3 x 10⁸ m/s

Therefore,

[tex]\lambda = \frac{3\ x\ 10^8\ m/s}{1.02\ x\ 10^8\ Hz}[/tex]

λ = 2.94 m (in meters)

λ = (2.94 m)(10⁹nm / 1 m)

λ = 2.94 x 10⁹ nm (in nanometers)

λ = (2.94 m)(10¹⁰ A / 1 m)

λ = 2.94 x 10¹⁰ A (in angstrom)

Answer:

Because warm air is less dense

Explanation:

Answer:

its the lunar and solar eclipse

Explanation:

the solar eclipse happens when the moon is in between the sun and earth

Answer:

53∘

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