What is a control group?

Answer:

hope this document helps! it's kinda hard to type out the explanation but ill try

Explanation:

divide the percenatge by the molar mass of the element.

(do this for both elements) \

find the lowest number and divide the results with it

now you have your empirical formula (with the rounded answers)

then find the molar mass of your empirical formula

divide the number given (267) by the molar mass to get a rounded number.

multiply that rounded answer to your empirical formula to get your empirical formula. :)

hope this can help you

you can search on google some stuff like your question

Answer:it's either the first or second one

Explanation:

the layers of the earth

Answer:

23.33%

Explanation:

from

percent yield=(mass÷total mass )×100%

Answer:

Circulatory System

Explanation:

Blood carries oxygen to the rest of the body, as well as glucose.

Answer:

it's both cold and hot weather so it could form a tornado

Answer:

Half life = 7.2 seconds

Explanation:

[tex]from \: decay \: equation \\ 2.303 log( \frac{n.}{nt} ) = kt \\ 2.303 log( \frac{50}{12.5} ) = k \times 14.4 \\ k = \frac{2.303 log( \frac{50}{12.5} )}{14.4} \\ k = 0.096288 {s}^{ - 1} \\ since \: half \: life = \frac{ ln(2) }{k} \\ half \: life = \frac{ ln(2) }{0.096288} \\ half \: life = 7.2 \: seconds[/tex]

Answer:

A. 7.56

b. 57.12

Explanation:

Hope that's right have a nice day :)

Answer:

They each have the same number of protons.

Explanation:

Answer:

They each have the same number of protons

Explanation:

All uranium isotopes have 92 protons in their nucleus. However, they differ in the number of neutrons in the nucleus, hence this also translates to varying mass numbers (which is the sum of neutrons and protons in the nucleus). The most common isotopes of uranium are; U-238, U-235, and U-234

Answer:

25

Explantion:

atomic no. =  no. of eletron

In any chemical process, the matter is neither lost nor gained according to conservation of matter. Therefore, the correct option is option B.

Matter is any material that has weight and occupies space by having volume in classical physics as well as general chemistry. All common items that can be felt are ultimately constituted of atoms, which are composed of colliding subatomic particles, therefore "matter" typically comprises atoms and everything made up of them, as well as any particles that act as if they both rest weight and volume.

It does not, however, contain massless particles like photons or even other energy phenomena and waves like light or heat. There are numerous states of matter (also known as phases). In any chemical process, the matter is neither lost nor gained according to conservation of matter.

Therefore, the correct option is option B.

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Answer:  Edgy, 2020

Explanation:    <3

Answer:

refer to picture below :)

Explanation:

There is a way to decrease the concentration of an ion here. The carbonate ion happens to be easy to decrease. All we have to do is add some acid (say HCl) to the container. The following sequence of reactions explains how this WO r ks.

As long as more acid is added, this process will continue until all the solid Zn CO3 has been dissolved

Answer:

Fungi, bacteria, ferns,

Explanation:

bacteria Fungi Ferns are important. decomposers,

I hope it helps you.

There are basically four different categories of decomposers: fungi, insects, earthworms, and bacteria. Fungi, ferns and bacteria are common decomposers.

Decomposers are organisms that disintegrate rotting or dead species; they carry out decomposition, a process only some kingdoms, like fungi, are capable of.

The primary decomposers in nature are fungi, which destroy organic material that would otherwise not be recycled.

Scavengers and decomposers are the two different categories of decomposers. Animals called scavengers hunt down dead plants or animals and consume them. They cut them into small pieces when they eat them.

Each contributes to the food recycling process differently. To transform dead plants or animals into simple substances, fungi release compounds. Some of these elements are absorbed by them for growth, while others go into the soil.

Thus, Fungi, ferns and bacteria are common decomposers.

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Answer:

May be 119 elements are artificially made.

Answer:

119 elements are artificially made...

Answer:

2.19moles

Explanation:

mole = mass ÷ molar mass

Molar Mass of the compound, C135H96O9NS =

12(135) + 1(96) + 16(9) + 14 + 32

= 1620 + 96 + 144 + 14 + 32

= 1906g/mol

Next, we calculate the mass percent of Oxygen in the compound

O9 = 16(9) = 144g/mol

144/1906 × 100

= 0.0755 × 100

= 7.55%

This means that there are 0.0755g of Oxygen in 1 mole of the coal compound.

Hence, in 29.1 moles of coal, there would be 29.1 × 0.0755

= 2.19moles of Oxygen

Answer:

Helium, this noble gas has the least density at STP

Explanation:

Answer: B. When two clear, colorless liquids are mixed together, a white solid forms.

D. A white piece of paper turns black and gives off a smell when burned.​

Explanation:

A. A white powder mixed with a clear, colorless liquid makes a solution that is also a clear, colorless liquid. B. When two clear, colorless liquids are mixed together, a white solid forms. O C. A shiny metal bar glows red and expands when heated. D. A white piece of paper turns black and gives off a smell when burned.​

When two clear, colorless liquids are mixed together, a white solid forms. A white piece of paper turns black and gives off a smell when burned.​ These two options are examples of chemical changes.

Chemical change, or, alternatively, chemical breakdown into two or more separate molecules, occurs when one material reacts with another to create a new substance. These processes are referred to as chemical reactions, and they are typically irreversible barring additional chemical reactions.

A chemical transformation is one in which one or more new compounds are created. Chemical reactions are another name for a chemical transformation. Examples include burning any stuff and iron rusting.

Chemical synthesis, or, alternatively, chemical breakdown into two or more separate molecules, occurs when one material reacts with another to create a new substance. These processes are referred to as chemical reactions, and they are typically irreversible barring additional chemical reactions.

Thus, option B and D are correct.

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Answer:

What is the name of the lab tool that is used to transfer a sample to a microscope slide?

A-a dropper

C-scissors

D-a ruler

Explanation:

got it wrong but this is the answer edg 2021

In the preparation of a microscopic slide, the items which are used are medicine dropper, scissors, and a slip cover. Thus, the correct option is D.

Microscope slides are made for the purpose of observations of different objects. After the observation, the slides are discarded. In most cases, the slides use a liquid mounting medium such as water or glycerin.

The procedure for the preparation of the slide is as follows:

1. Place a drop of liquid mounting medium in the center of the slide.

2. Position the sample on liquid with the use of tweezers.

3. At an angle, place one side of the cover slip against the microscopic slide making contact with outer edge of the liquid drop.

4. Lower the cover slip slowly, avoiding air bubbles.

5. Remove the excess water present in it with the help of paper towel.

Therefore, the correct option is D.

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Answer:

C 6 H 12 O 6 + 6 O 2 --> 6 CO 2 + 6 H 2 O + ATP is the complete balanced chemical formula for cellular respiration.

Answer:

C6H12O6 + 6O2 -> 6CO2 + 6H2O + 38ATP

Explanation:

glucose + oxygen gas -> carbon dioxide + water + ATP

Answer:

mixture

Explanation:

Answer:

Mixture

Explanation:

Answer:

1)

Hg

80 protons, 80 electrons, 121 neutrons

2)

Mo

42 protons, 42 electrons, 54 neutrons

3)

Symbol is Cu, Mass is 64, 29 Protons

4)

C

Atomic number is 6, 6 protons, 6 electrons, 6 neutrons

5)

Symbol is P, 15 protons, 15 electrons, 16 neutrons

6)

Pb

Atomic number is 82, 82 electrons, 125 neutrons

7)

Na

Mass is 23, 11 protons, 11 electrons.

Hopefully this helps!

Volume of Ammonia(NH₃) = 22.4 L

Given

Reaction

3CuO+2NH₃⇒ 3Cu + 3H₂O+ N₂

In the problem, the CuO coefficient should be 3 not 2

M CuO = 80

mass CuO = 120 g

Required

The volume of NH₃

Solution

mol CuO :

[tex]\tt mol=\dfrac{mass}{M}\\\\mol=\frac{120}{80}\\\\mol=1.5[/tex]

From the equation, mol ratio CuO : NH₃ = 3 : 2, so mol NH₃=

[tex]\tt \dfrac{2}{3}\times 1.5=1~mol[/tex]

Assume at STP(0 °C, 1 atm) ⇒1 mol = 22.4 L, then volume of NH₃=22.4 L

Answer:

the answer is 1

the  coefficient needed to balance this equation is 1

Explanation:

Answer:

I think crystallization is a write answer for this question

Explanation:

but according to this (E is the write answer)

Answer:

Approximately [tex]0.35\; \rm W[/tex] on average.

Explanation:

There are multiple to find power:

The question did not state the speed at which the arm of the chipmunk moves. However, the question did state the work done ([tex]W = 0.70\; \rm J[/tex]) and the time required ([tex]t = 2\; \rm s[/tex]).

Therefore, the equation [tex]P = W / t[/tex] seem to be more suitable.

[tex]\begin{aligned}&P\\ &= \frac{W}{t} \\ &= \frac{0.70\; \rm J}{2\; \rm s} \approx 0.35\; \rm W\end{aligned}[/tex].

Answer:

True

Explanation:

Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage.

For those of us interested in the water cycle, sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water which bypasses the conversion to liquid stage and goes straight to the gaseous form.