:answer question number 5

Answer:

1. rolled paper tubes filled with black powder (also called gunpowder), are made.

2. Sometimes they are filled with flash paper and a fuse.

3. When the fuse of a firecracker gets lit, the fire burns along the fuse.

4. Then it eventually reaches the powder, and explodes.

Explanation:

Answer:

Wavelength can be calculated using the following formula: wavelength = wave velocity/frequency. Wavelength usually is expressed in units of meters. The symbol for wavelength is the Greek lambda λ, so λ = v/f.

Explanation:

Just a formula that's commonly used in biology.

Answer:

LiCI

Explanation:

CO and No2 are both covalent compounds and it was a 50 50 and I guessed the right answer.

The one that is an ionic compound is LiCl. The correct option is A.

Ionic compounds are those compounds that have one negative and one positive charge molecule. When this negative and positive charge joins together, the compound becomes neutral.  Electrostatic force joins these elements.

LiCl is a salt that is formed by the joining of lithium with chloride. Lithium is positively charged and chlorine is negatively charged. One identity of this compound is that it is a neutral salt, so it can be identified as an ionic compound. When they disjoint, they form a crystal-like structure.

An example of an ionic compound is sodium chloride, in which sodium is positive and chloride is negative.

Therefore, the correct option is A. LiCl.

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Answer:

CLEANER

Explanation:

Independent variable is the variable in an experiment that is changed or manipulated by the experimenter in order to bring about a measurable response.

In this question, Marie notices that the current cleaner she is using on her shower is not cutting through the hard water build-up that has accumulated. She decides to purchase 3 other cleaners to see if one of them will do a better job of cutting through the stains. The CLEANERS being changed in this experiment is the INDEPENDENT VARIABLE.

Answer:

Condensation

Explanation:

Answer:

In ionic compounds, the charges of constituent ions must balance. This can be achieved by having three sodium ions per nitride ion. Therefore, the formula of sodium nitride is Na3N

Explanation:

Answer:

the charges of constituent ions must balance. This can be achieved by having three sodium ions per nitride ion. Therefore, the formula of sodium nitride is Na3N

Explanation:

Answer:

The aluminium is impure

Answer:

Just go out there and be yourself brother!

Explanation:

If she doesn't like you, she doesn't like the real you, therefore you don't deserve her! lol

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\ [/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{1.49 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1.49}{6.02} \\ = 0.247508305...[/tex]

We have the final answer as

Hope this helps you

Answer:

Option (a) is the correct answer.

Explanation:

The law of conservation of energy states that energy can neither be created nor it can be destroyed. It can only be transformed from one form to another.

Therefore, the total amount of energy before and after a chemical reaction is the same. Thus, energy is conserved.

Therefore, we can conclude that option (a) is the correct answer.

Answer:

conserved

Explanation:

law of conservation of energy says that energy can neither be created or destroyed

Answer:

See explanation

Explanation:

The general formula used to obtain the frequency of a wave is;

v=λf

where;

v = speed of the wave

λ= wavelength of the wave

f= frequency of the wave.

Now, the speed and wavelength of light in various media are known.

If we plug the value of the speed of light and the wavelength of light into the formula given above, we can obtain the frequency of light.

The frequency of a photon of light can also be obtained from Plank's equation;

E= hf

where;

E =energy of the photon of light

h = Plank's constant

f= frequency of the photon.

This is used when the energy of the photon of light is supplied or can be calculated using the wavelength of light provided in the problem.

Answer #1: Lithospheric plates are part of a planetary scale thermal convection system. The energy source for plate tectonics is Earth's internal heat while the forces moving the plates are the “ridge push” and “slab pull” gravity forces. It was once thought that mantle convection could drive plate motions.

Answer #2:Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to high gravitational potential energy into the mantle. Subduction zones are sites that usually have a high rate of volcanism and earthquakes.

hope you find what you looking for

Answer:

1.) False?

2.) true. sorry english not my first language

Answer:

Explanation:

Building bricks deteriorate overtime due to chemical weathering from moisture constantly in contact with it overtime, as well temperature changes. Their topmost layers leach after continuous attack, and are eroded. thereby causing them to break away most times.

This cycle takes place overtime and is not a quick action.

I hope this is easy to understand.

Answer:

5 x 10 x 3200 = 170 000J or 170kJ

Explanation:

i searched it lol

The energy needed to raise the temperature of a 5 kg block of concrete by 10° C is 170 000J or 170kJ.

Energy is defined as a quantitative property that is transferred to a body or to a physical system. It can also be defined as capacity of doing work.

There are basically five forms of energy

Heat energy = mass x heat capacity x raise in temperature

                     = 5 x 3200 x 10

                     = 170000 J or 170 kJ

Thus, the energy needed to raise the temperature of a 5 kg block of concrete by 10° C is 170 000J or 170kJ.

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Answer:

bf v

Explanation:

bgf

Explanation:

1) from the periodic table for example if u looking for K it is from the group 1A so the valancey = +1 that is mean it loses one electron to reach a stable state. and this applied for the 1A , 2A, 3A groups.

if u looking for N it is from group 5A so its valency is -3

so it gain 3 electrons to reach a stable state to complete its orbital to 8 electrons. this applied to 5A, 6A,7A

for the transition metals and simimetals other rules.

2) neutral if the element does not hold any charge like

H2, O2, N2, Fe, Au, Cu ...

isotope : if the 2 elements have same symbol and atomic number but they differ in the mass number because the have different numbers of neutrons.

if the element is charged then it is considered as an ion ex: Fe2+ then it is iron cation ( +ion)

F- then it is fluoride anion (-ion)

if u have any doubt just writ a comment ( ;

The question is incomplete, the complete question is; During a conference presentation, a scientist described the materials that she used and how she performed her experiments.

Which best explains why a scientist would share these details in a conference?

It tells the audience if the results support or contradict the hypothesis.

It tells the peers if the study is supported by mathematical models.

It informs the peers if the results are supported by other scientists.

It informs the audience if the study included controlled tests.

Answer:

It informs the audience if the study included controlled tests.

Explanation:

Usually, scientific conferences involve presentation of papers by scientists. These paper presentations are actually the sharing of details of the scientific research carried out by other scientists.

Presenting the materials and methods section of the a research project  to a scientific conference informs the audience if the study included controlled tests.

The inclusion of controlled tests in a scientific study enhances the validity of the results obtained in the study.

Answer:

answer on what no file attached

Explanation:

Answer:

Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there. first question Natural non-living things: They are found in nature and are not made by man. Examples: Sun, moon, stars, sky, clouds, rocks, mountains and many more. Man-made non-living things: They are made by man. Examples: Toys, chairs, tables, beds, houses, buildings, trains and many more. second question Metamorphic rocks form from heat and pressure changing the original or parent rock into a completely new rock. The parent rock can be either sedimentary, igneous, or even another metamorphic rock. The word "metamorphic" comes from Greek and means "To Change Form". third question. Sedimentary. fourth question and sorry I can't answer the last :(

Explanation:

Answer:

CH4 - Methane

B2Si - Diboron monosilicide

N2O5 - Dinitrogen pentoxide

CO2 - Carbon dioxide

Explanation:

When it comes to naming covalent compounds, there are several rules.

The name is derived based on the formula. For example, N2O5. The first element is nitrogen. To the name of the element, you add the prefix that tells us how many of its atoms are in the compound. In this case, there are two atoms, which means that the prefix will be di- (dinitrogen). The second element is oxygen. You are supposed to take only the root of the second element's name and then add the prefix denoting the number of its atoms and the suffix -ide (pentoxide). This is how we'll get dinitrogen pentoxide.

The only exception is methane (CH4), which is an organic compound. Organic compounds are named using the IUPAC nomenclature.

Answer:

The correct option is;

It is always necessary to include a Roman numeral after the symbol of the metal

Explanation:

The transition metals can form ionic compounds with other elements by giving different number of electrons such that the transition metals can combine to form compounds in which they have different oxidation states

Therefore, in a compound formed by a transition metal, the value of the transition metal's valency or oxidation state in the compound is indicated by the inclusion of an equivalent Roman numeral after the transition metal in the name of the chemical formula of the compound

Answer:

bug vfyjovcduvcu Harris's

[tex] \sf \: Answer \: 8 \: :[/tex]

→ During the formation of a chemical bond, heat is released.

[tex] \sf \: Answer \: 9 \: :[/tex]

→ Solution that contains all the solute it can hold at a given temperature is saturated.

[tex] \sf \: Answer \: 10\: :[/tex]

→ No. of neutrons present in Bromine are 44

Answer:  B. They show the elements that make up a compound

Explanation:

Answer:

B

Explanation:

Answer:

That means that the isotope that has a mass number of 28 is probably the most abundant. This is because your average atomic mass is 28.086 amu, which is closest to 28.

Formula used to calculate average atomic mass follows:

average atomic mass=(atomic mass of an isotope)*(fractional abundance)

we are given=

Three isotopes of Silicon, which are Si-28, Si-29 and Si-30.

Average atomic mass of silicon = 28.086 amu

As, the average atomic mass of silicon is closer to the mass of Si-28 isotope. This means that the relative abundance of this isotope is the highest as compared to the other two isotopes.

Percentage abundance of Si-28 isotope = 92.2%

Percentage abundance of Si-29 isotope = 4.7 %

Percentage abundance of Si-30 isotope = 3.1%

Hence, the abundance of Si-28 isotope is the highest as compared to the other isotopes.

Answer:

4.91

Explanation:

From the given information:

The millimoles of aniline = 100* 0.3065 = 30.65

30.65 millimoles HNO3 must be added to reach the equivalence point.

30.65 = V x 0.5774

V = 30.65/0.5774

V = 53.08 mL HNO3 must be added

Thus, total volume = 53.08 + 100 = 153.08 mL

[salt] = 30.65 /  153.08 = 0.20022 M

At equivalence point :

pOH = 1/2 [pKw + pKb + logC]

pOH = 1/2 [14 + 4.87 + log 0.20022 ]

pOH =9.086

pH = 14 - 9.086

pH = 4.914

pH ≅ 4.91 to 2 decimal places.

Answer:

the last one

Explanation:

I'm pretty sure

Answer:

Particles on each are constantly moving (the last one)

Answer:

Explanation:

there's no options that you put but usually if you add more of the reactant the rate will increase, adding a catalyst will increase the rate, and increasing the temperature if it's endothermic