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Answer:

b

Explanation:

Answer: d:the color change that takes place after heat melts and begins to decompose the sugar

Explanation:i did the study island

Answer: A is a decomposition reaction, and B is a synthesis reaction

Explanation: the first equation shows the reactant breaking up into 2 parts aka decomposition and equation 2 shows the reaction being combined into one part, aka synthesis. hope that helps!

Answer:

Answer d

Explanation:

Answer:

Burning fossil fuels emits a number of air pollutants that are harmful to both the environment and public health. Sulfur dioxide (SO2) emissions ...

Answer:

Valence electrons are the outermost of  electrons.

Explanation:

valence electrons are the outermost electrons of an atom located in the shell/ orbit

Answer:

Explanation:

IIA elements in the periodic table are the alkali earth metals

Answer:

A. The initial mass of the sample is 6.35

B. The time taken for 0.3 mg of the sample to remain is 66 days

A. Determination of the initial mass of the sample

Half-life (t½) = 15 days

Time (t) = 10 days

n = t / t½

n = 10 / 15

Number of half-lives (n) = ⅔

Amount remaining (N) = 4 mg

[tex]N_0 = N \times {2}^{n} \\ N_0 = 4 \times {2}^{2 \div 3} \\ N_0 = 6.35 \: mg[/tex]

Therefore, the initial mass of the sample is 6.35 mg

B. Determination of the time

Amount remaining (N) = 0.3 mg

Initial amount (N₀) = 6.35 mg

[tex]{2}^{n} = \frac{N_0}{N} \\ \\ {2}^{n} = \frac{6.35}{0.3} \\ \\ {2}^{n} = 21.167 \\ take \: the \: log \: of \: both \: side \\ log \: {2}^{n} = log \: 21.167 \\ nlog2 = log \: 21.167 \\ divide \: both \: side \: by \: log2 \\ \\ n = \frac{log \: 21.167}{log2} \\ \\ n = 4.4[/tex]

Number of half-lives (n) = 4.4

Half-life (t½) = 15 days

t = n × t½

t = 4.4 × 15

Therefore, it will take 66 days for 0.3 mg of the sample to remain.

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Answer:

Explanation:

They play a very important part. The geometry is not a straight line. It is an angle over 90 which means that the molecule has the same general shape as a boomerang. The two hydrogens and the 2 lone electron pairs try to get away as far as possible from each other. The actual shape results in a tetrahedron shape. But the two hydrogens and 1 oxygen actually look like the aforementioned boomerang.

Answer:

Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. A chemical substance is composed of one type of atom or molecule.

Hope this helps :)

Answer:

iron

iron has +2 valancy

Answer:

C silver

Explanation:

Answer:

You have to remember this memory aid, diagonals and all.

You have to keep a tight tally of the electrons you’ve used so far so you don’t go over the number of electrons in the element you’re working on.

You have to remember how many electrons fit into each subshell (s, p, d, f).

It takes a lot of time, especially when the element has more than 20 electrons.

Explanation:

Answer:

h and o

Explanation:

because both are non metals

Answer:

In the presence of UV light, ethane will react with bromine in a substitution reaction. UV light is the condition under which the reaction will occur so it is written above the arrow in the chemical equation. As the reaction proceeds, the intensity of the re-brown colour of the bromine water decreases.

Answer:

here ya go

Explanation:

combining bromine and ethane leads to a brown gas or liquid which is made of the elements. it is a gas at room temperature and does not affect human beings. there are many uses for bromine compounds but they are mainly used for the manufacturing of chlorine, fire retadants, water purification, graphy chemicals and pharmaceutcals. it is a naturally occurring element that can be found in animals such as sharks since they produce their own.

Answer:

the difference is  the presence of a carbon atom

Explanation:

Answer:

3.08x10^25

Explanation:

Divide the mass in grams by the molar mass of nitrogen (14.0067), then multiply the result by Avogadro's number (6.022x10^23). Then round to the correct amount of significant figures.

The frequency of yellow light, which has a wavelength of 5.56 x 10^-7 m is  5.40 x 10^14 Hz. Therefore, option B is correct.

The distance between identical points (adjacent crests) in adjacent cycles of a waveform signal propagated in space or along a wire is defined as the wavelength. This length is typically specified in wireless systems in meters (m), centimeters (cm), or millimeters (mm) (mm).

The wavelength is the distance between two wave crests, and it is also the distance between two wave troughs. The frequency is measured in cycles per second (Hz) and is the number of vibrations that pass over a given spot in one second (Hertz).

Speed is distance over time, Therefore, v = λ / T.

The frequency, f, is 1/T, so the equation relating wave speed, frequency, and wavelength is v = c / λ .

Given :

Wavelength = 5.56 x 10^-7 m

Frequency = ?

Speed (c) = 3 × 10⁸m/s

v = c / λ

By substituting given values in equation and we get,

v =  3 × 10⁸ / 5.56 x 10^-7

= 5.40 x 10^14

The frequency of yellow light is 5.40 x 10^14.

Thus, option B is correct.

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Hi

In the modern periodic table, the elements are arranged in the order of their increasing atomic number. In the modern periodic table, there are seven horizontal rows called periods and eighteen vertical columns (1 to 18) called groups. The arrangement of the periods and groups results in formation of boxes.

Explanation:

If it's help pls give me Brainliest!!

Answer:

Explanation:

1) Organic compounds always contain only p-block elements (Groups III-VII), at least one of which must be carbon. 2) Organic compounds almost always contain one or more C-H bonds. ... Thus, all bonds are typically covalent in organic compounds. Methane (CH4) is the prototypical organic molecule.

Methane contains carbon, forming covalent bonds, and is found in living organisms, making it an organic compound.

Methane (CH₄) is considered an organic compound due to its molecular structure and occurrence in living organisms. Organic compounds are primarily composed of carbon atoms covalently bonded to hydrogen and often other elements like oxygen, nitrogen, sulfur, and more.

Methane consists of one carbon atom bonded to four hydrogen atoms through covalent bonds. Carbon's unique ability to form stable covalent bonds with other elements, including itself, leads to the vast diversity of organic molecules found in living organisms.

Methane is a crucial component of natural gas and is produced by various biological and geological processes. It is present in the digestive systems of animals, formed during decomposition, and plays a role in carbon and energy cycles.

Its prevalence in living systems and its molecular structure classify methane as an organic compound, reflecting the foundational principles of organic chemistry.

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The complete question is :

Methane is called an organic compound why​?

Answer:

This happens because a metal is less reactive than carbon and it can be extracted from its oxides by heating with carbon. The carbon displaces metal from the compound and removes the oxygen from the oxide.

Answer:

3) A single specific wavelength

Explanation:

When an electron returns to ground state, it has to emit a single photon.

When a single electron returns to the ground state from an excited state, it emits a single, specific wavelength of light. Therefore, option 3 is correct.

The separation between any two points in a wave and those identical points in the following wave cycle. This can be null-to-null, crest-to-crest, trough-to-trough, etc.

A spectrum is the term used to describe the range of wavelengths or frequencies for wave phenomena. The term was originally used to describe the electromagnetic spectrum, but it is now used to describe the sound spectrum and vibration spectrum.

When electromagnetic radiation such as radio waves, light waves, or infrared waves travel across space, they leave behind distinctive patterns. Each wave has a distinct size and form. Wavelength is the separation between peaks.

Thus, option 3 is correct.

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Answer:

Synthesis

Explanation:

Trust me on this :)

Answer:

i think its solar radiation

Answer:

Explanation:

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

[tex]d = \frac{m}{v} \\ [/tex]

m is the mass

v is the volume

From the question

m = 149.8 g

v = 12.1 mL

We have

[tex]d = \frac{149.8}{12.1} = 12.380165... \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

Callable or redeemable bonds

Explanation:

"..are bonds that can be redeemed or paid off by the issuer prior to the bonds' maturity date."

Answer:

Explanation:

The balanced equation says that we'll get 1 mole of H2 for every 1 mole of Mg.  50 grams of H is 50g/2 g/mole = 25 moles of H2.  That means we'll need 25 moles of Mg.  Convert that into grams:  (25 moles Mg)*(24.3 g/mole) = 607 grams Mg.  

At STP, all gases occupy 22.4 liters/miole.  That means 25 moles of H2 would occupy (25 moles)*(22.4 liters/mole) = 560 liters.