2.1 x 10^-3 x 2 x 10^2 =


a)
4.2 x 10^-5

b)
4.2 x 10^-1

c)
4.2 x 10^1

d)
4.2 x 10^-6

Answers

Answer 1

Answer:

I believe it is B

Explanation:

hope it helps. please let me know if it's wrong


Related Questions

Can someone balance these equations?

Answers

This is mind numbing, but I got you.

3NaOH + 1FeCl3 = 1Fe(OH)3 + 3NaCl

3Mg + 2H3(PO)4 = 1Mg(PO4)2 + 3H2

What is meant by the dual wave-particle nature of light?

Answers

In physics and chemistry, wave-particle duality holds that light and matter exhibit properties of both waves and of particles. ... The idea of duality is rooted in a debate over the nature of light and matter dating back to the 1600s, when competing theories of light were proposed by Christiaan Huygens and Isaac Newton. I Hope this helps you. Lol

Dual wave particle nature of light  can be regarded as mechanism that says light and matter will also has the properties of  waves as well as that of  particles.

This concept is found in mechanics as it describes how light and matter also has the properties associated with waves as well as particles.

The duality explained inadequacy of conventional concepts of both wave and particle so as to give explanation about behaviour of quantum objects.

the dual nature of light made us to understand that light has wave properties and it also has particle properties.

Some of the properties of wave that light has are:

wavelengthspeed

Therefore, duality means have both characteristics of light and wave

Learn more at,: https://brainly.com/question/14326678?referrer=searchResults

Why does forming bonds release energy? *

Answers

Bonds are stable configurations of (relative) minimal energy. So when entering a bond the combined energy level of the contributing atoms is being reduced to a local minimum. That way “free energy” is released that shows as heat or radiation (e.g.) in the environment.

pls help science

Which description properly describes the plant structures involved in photosynthesis?

Stomata take in water, sunlight, and carbon dioxide and release oxygen.
Phloem transports water, stomata take in carbon dioxide, and chlorophyll absorbs sunlight.
Xylem takes in water, sunlight, and carbon dioxide and releases oxygen.
Stomata take in carbon dioxide and release oxygen.

Answers

Answer:

Stomata take in water, sunlight, and carbon dioxide and release oxygen.

Explanation:

Photosynthesis collects and absorbs sunlight and converts the sunlight into sugars (glycose), then the plant stores the sugar and uses it.

27.2Pb(NO3)2 --> 2Pb0 + 4NO2 + O2
O A. Synthesis
B. Single displacement
C. Decomposition
D. Combustion

Answers

The answer is c decomposition.

Atoms combine in whole-numbcher ratios.​

Answers

Ummm is there a picture u needed to attach orrrrrm

Can you please help me with this question

Answers

Answer:

First blank: spiral arms

Second blank: center

Explanation:

find the percent composition of lead in lead (II) nitrate. round to 2 significant figures.​

Answers

Answer/Explanation:

62.559%

mass of an element   X 100%

mass of the compound

Scientific Notation: 3.45 x 10^5

E Notation: 3.45e5

35 points
What are the reactants and the products in this equation?

2H2 + O2 → 2H2O


a Reactants: water; Products: hydrogen, oxygen

b Reactants: hydrogen, oxygen; Products: water

Answers

Answer:

02 ;D h2oooooooooooo

long story shortB

Explanation:

Answer:

B

Explanation:

2H2→Hydrogen peroxide

O2→oxygen

"A water molecule (formally known as dihydrogen monoxide) is composed of two hydrogen atoms and one oxygen atom. ... The actual reaction to make water is a bit more complicated: 2H2 + O2 = 2H2O + Energy"

"A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction."

The answer is B, hope this helps :)

To Identify a mineral, there are tests that are used including:

Answers

Geologists use the following tests to distinguish minerals and the rocks they make: hardness, color, streak, luster, cleavage and chemical reaction.

Please help... giving a lot of points and awarding brainliest.

Answers

Theoretical Yield of H2SO3: 31.2 g
Percent Yield: 67.4%

Theoretical Yield of C2H6: 6.50
Percent Yield: 88.7%

Theoretical Yield of HF: 3.84
Percent Yield: 71.4%

Is Mg(CH3COO)2 soluble or insoluble

Answers

Answer:

It is Soluble

Explanation:

Name- Magnesium acetate

It dissolves easily in water and alcohol.

how can acids cause chemical weathering

Answers

Acid rain slowly dissolves rocks due to chemical reactions between the acid and the minerals in the rock. Differential Weathering: Softer, less resistant rocks wear away at a faster rate than more weather resistant rocks. More exposure to acid rain results in more rapid weathering.

The acids react with the chemical composition of the rock causes the disintegration of the rocks.

Chemicals when react with the chemical components of the rocks cause the disintegration of the chemical and physical structure of rocks which cause breakage of rocks into parts. This process is called chemical weathering.

For example, the sulfur dioxide gas in the air reacts with the water in the air to form the acid rain.

The acid rain reacts with the chalk or limestone rock that causes the disintegration of the chemical structure and physical structure of rock causing breakage of the chalk or limestone.

Learn more about weathering:

https://brainly.com/question/14426457

what is cell explain in a paragraph

Answers

Answer:

Cells are the basic building blocks of living things. The human body is composed of trillions of cells, all with their own specialised function. Cells are the basic structures of all living organisms. Cells provide structure for the body, take in nutrients from food and carry out important functions.

5. __HCl + __NaOH-> __NaCl + __H2O

6. __FeS + __HCl-> __H2S + __FeCl2

7. __C2H4 + __O2-> __CO2 + __H2O

INEEDHELP

Answers

Answer:

umm is this free points? cause this looks very ummm weird

Explanation:

What force pulled the solar system together out of a cloud of gas and dust

Answers

gravity
Approximately 4.5 billion years ago, gravity pulled a cloud of dust and gas together to form our solar system.

What type of
energy travels in the form of electromagnetic waves?

A: Chemical Energy
B: Gravitational Energy
C: Nuclear Energy
D: Radiant Energy

Answers

Gravitational energy.

Answer:

Radiant Energy

Explanation:

Radiant energy is created through electromagnetic waves

Help please I need it!

Answers

I think it’s V snowing

The best description of the Big Bang Theory is ______________
A. The universe began with cold dense energy compressing into matter after which all matter and energy began rapidly contracting toward each other.

B. The universe began with hot dense energy compressing into matter after which all matter and energy began rapidly expanding away from each other.

C. The universe began with hot dense matter after which all energy began rapidly expanding away from each other.

D. The universe began with cold, spread out matter compressing into energy, after which all matter and energy began slowly moving toward each other

Answers

The answer is the letter “c”

Answer:

B. the universe began with hot dense energy compressing into matter after which all matter and energy began to rapidly expanding away from each other.

hope it helps

PLEASE HELP ASAP!!!
A teacher wrote the following part of a chemical equation involving water (H2O) and carbon dioxide (CO2): H2O + CO2 ---> ?
What is the most likely result of the chemical reaction represented by this equation?
A. H2CO3
B. NaCl
C. HNO3
D. H2Ca3

Answers

Answer:

Id say A. I think I hope I'm right

State the law of multiple proportions.

Answers

Statement that when two elements combine with each other to from more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

Answer:

Law of Multiple proportion states that when two elements combine to form more than one compound, the mass of one element, which combines with a fixed mass of the other element, will always be ratios of whole numbers. For example, let us assume 2 molecules CO (carbon monoxide) and CO2(carbon dioxide).

Explanation:

how many grams of sodium carbonate must react with 222 g of calcium chloride to make 233 grams of sodium chloride and 201 grams of calcium carbonate?

Answers

Answer: 212 g  of sodium carbonate must react

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products formed must be equal to the mass of reactants taken.

In order to get the same mass on both sides, the atoms of each element must be balanced on both sides of the chemical equation.

The balanced chemical equation is:

[tex]Na_2CO_3+CaCl_2\rightarrow 2NaCl+CaCO_3[/tex]

Mass of products = mass of  sodium chloride + mass of  calcium carbonate = 233 g+ 201 g= 434 g

Mass of reactants= mass of sodium carbonate  + mass of calcium chloride =x + 222 g

As the mass of reactants should be equal to mass of products

434  = x  + 222 g

x = 212 g

Thus 212 g  of sodium carbonate must react with 222 g of calcium chloride to make 233 grams of sodium chloride and 201 grams of calcium carbonate

Explain how to identify a starting position on a line.

Answers

Displacement is defined as the distance, in any direction, of an object relative to the position of another object. Physicists use the concept of a position vector as a graphical tool to visualize displacements. A position vector expresses the positionof an object from the origin of a coordinate system

Answer:

Pick a reference point on the line to be the zero position. Determine the direction and measure the distance from zero in standard units.

Explanation:

how can a substance stay at a certain temperature even though it is being heated?​

Answers

The temperature of a certain substance can be seen as the average speed of the atoms or molecules in that substance. In the liquid state of a substance the forces between the atoms or molecules are strong enough to keep them together, however with enough freedom to move, unlike in the solid state. If we would have a closer look at the surface of a liquid from sideways, we would see water molecules jumping out of the water and reentering it again. The lower the water temperature would be the lesser the amount of water molecules leaving the liquid phase would be. If water would be heated up and the temperature will reach 100 degrees C at normal atmospheric pressure, more water molecules would leave the water than reentering. Boiling has started. The temperature of the water remains at 100 degrees C, if the heating continues as the average speed of molecules will not increase, only the rate of molecules leaving the water will increase, until all the water in liquid state has been vapourized. The amount of heat needed to vapourize liquid water is called latent heat. Latent heat is a very important driving factor in the atmosphere and thus the weather.

How did chemists change Mendeleev's periodic table in the early 1900s?

Answers

Answer:

They used atomic number instead of atomic mass to organize the elements. From an element's location in the periodic table, you can predict: ... The elements have similar properties.

Explain why Chlorine has the largest electronegativity between Ne, Mg, Ba, Sb, Hg, Li?

Answers

Answer:

Look at the image provided and try work it out. I don't have the time but I hope I helped you!

Explanation:

how does activation energy influence a reaction

Answers

Answer: The activation energy of a particular reaction determines the rate at which it will proceed. The higher the activation energy, the slower the chemical reaction will be. The example of iron rusting illustrates an inherently slow reaction.

Explanation:

If it takes 5 hours to produce 8.0 kg of alcohol, how any days will it take to consume 1000 kg of glucose?

Answers

It takes 21.3 days

Further explanation

Given

5 hr = 8 kg Alcohol

Required

Days to consume 1000 kg of glucose

Solution

Alcoholic fermentation⇒ glucose produces ethanol and carbon dioxide,

C₆H₁₂O₆ → 2 C₂H₅OH + 2CO₂

mol ethanol :

[tex]\tt \dfrac{5000~g}{46~g/mol}=108.7~moles[/tex]

moles of glucose to produce 108.7 moles ethanol :

[tex]\tt \dfrac{1}{2}\times 108.7=54.35[/tex]

54.35 moles = 5 hours

moles of 1000 kg of glucose :

[tex]\tt \dfrac{10^6~g}{180~g/mol}=5555.5~moles[/tex]

So for 5555.5 moles, it takes :

[tex]\tt \dfrac{5555.5}{54.35}\times 5~hours=511.085~h=21.3~days[/tex]

Assume that a 100-base pair DNA double helix contains 45 cytosine bases. Use logical thinking to figure out how many adenine bases there will be. Explain how you know.

Answers

Answer:

You will not be allowed to have any learning aids while taking a test or ... A DNA molecule consists of three parts—a nitrogen base, ... There are four DNA nucleotides, each with one of the four nitrogen bases (adenine, thymine, cytosine, and guanine). The DNA forms a two-stranded spiral, or double helix.

Explanation:

hope this helps ✌️

What three types of particles make up an atom? What are their charges?

Answers

Answer:

Protons, neutrons, and electrons are the three main subatomic particles found in an atom. Protons have a positive (+) charge. An easy way to remember this is to remember that both proton and positive start with the letter "P." Neutrons have no electrical charge.

Answer:

Protons, positive charge

Neutrons, neutral

Electrons, negative charge

Explanation:

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