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If 63.8 grams of aluminum metal (Al) react with 72.3 grams of sulfur (S) in a synthesis reaction, how many grams of the excess reactant will be left over when the reaction is complete? Be sure to write out the balanced equation for this reaction and to show all of your work.

The balanced chemical reaction would be:

16Al + 3S8 = 8Al2S3

We need to determine which reactants are the limiting and the excess. To determine this, we use the initial amounts of the reactants given above. We need to convert them into units of moles and use the balanced reaction to relate the substances calculating the amount needed to react all of the reactants. We do as follows:

63.8 g Al ( 1 mol Al / 26.98 g Al ) ( 3 mol S8 / 16 mol Al ) (256.48 g S / 1 mol S )= 113.72 g S8 needed to completely react
72.3 g S8 ( 1 mol S8 / 256.48 g S8) ( 16 mol Al / 3 mol S8 ) ( 26.98 g / mol ) = 40.56 g Al needed to completely react

Therefore, the excess would be Al and the limiting would be sulfur. The amount excess would be 63.8 g Al  – 40.56 g Al = 23.24 g Al

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Which is a non-polar molecule? A. Hydrogen Chloride (HCI) B.Oxygen Difluoride (OF2) C. Sulfur Hexachloride (SF6) D. Hydrogen Cyanide (HCN) E. Trifluoromethane (CHF3)

Which is a non-polar molecule? A. Hydrogen Chloride (HCI) B.Oxygen Difluoride (OF2) C. Sulfur Hexachloride (SF6) D. Hydrogen Cyanide (HCN) E. Trifluoromethane (CHF3)

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Which is the correct formula for sulfur dichloride

Which is the correct formula for sulfur dichloride

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What is the Noble gas notation of sulfur (S)?

The noble gas it is [Ne]

Explanation:

the noble gas notations are the electronic configuration of an element ( the amount of electrons that this element has ) but using as a reference the electronic configuration of the last noble gas of the previous Row.

In the case of sulphur we know that S has 16 electrons so the normal configurations would be until here this is the configuration of Ne that it is the previous noble gas before S.

So, instead of writing again the whole configuration we just write [Ne] and the rest of the configuration () to complete the number of electrons.

Another example is Mg where using noble gas notation its electronic configuration will be: [Ne]

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Atoms contain charged particles called protons and electrons. Each proton has a charge of +1, and each electron has a charge of –1. A sulfur ion has 16 protons and 18 electrons. Find the net charge.

Atoms contain charged particles called protons and electrons. Each proton has a charge of +1, and each electron has a charge of –1. A sulfur ion has 16 protons and 18 electrons. Find the net charge.

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Sulfur dioxide: a. creates a reddish-brown haze in the sky b. is a secondary air pollutant c. has an irritating odor and is colorless d. is relatively harmless to the environment

Helicases unwind the two parental DNA’s strands and creates the replication fork; single strand binding proteins keep the single strand from joining.

Further information:

• DNA replication: a biological method occurring in all living organisms that is the basis for biological inheritance

Helicase: It is an enzyme that may unwinds the DNA helix ahead of the replication machinery.

Origin of replication: a specific sequence in a genome at which replication is started.

Steps of DNA replication:

• During initiation, proteins fix to the source of replication while helicase unwinds the DNA helix and two replication forks are formed at the source of replication.

• During elongation, a primer sequence is added with complementary RNA nucleotides, which are then substituted by DNA nucleotides.

• During elongation the leading strand is made constantly, while the lagging strand is made in portions called Okazaki fragments.

• During termination, primers are detached and substituted with new DNA nucleotides and the backbone is stuck down by DNA ligase.

Purpose of DNA replication:

The purpose of DNA replication is to produce two duplicate copies of a DNA molecule. This is essential for cell division during development or repair of damaged tissues. DNA replication ensures that each new cell receives its own replica of the DNA.

Subject: Biology

Level: High school

Keywords:

• DNA replication

• Helicase

• Origin of replication

• Steps of DNA replication

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Which Of These Elements Has Four Valence Electrons? Hafnium Radon Silicon Sulfur

The double-slit experiment is a famous tool to illustrate concepts within quantum mechanics. In particular it demonstrates the concept of wave-particle duality. Use of a light wave demonstrates diffraction and interference, which is a typical wave behaviour. Surprisingly, use of a beam of electrons also yields an interference pattern, showing electrons can behave like waves.

Explanation:

There would be a optical phenomenon pattern almost like, however totally different from, that exploitation light-weight.Interference and optical phenomenon are the phenomena that distinguish waves from particles: waves interfere and split, particles don’t.

Light bends around obstacles like waves do, and it’s this bending that causes the one slit optical phenomenon pattern.

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Which are mixtures? Check all that apply. copper sulfate powdered sulfur and copper filings iron oxide cranberry juice air sugar beryllium

1. The right answer is polymerization.

Polymerization refers to the chemical reaction or process by which small molecules (eg hydrocarbons of two to ten carbon atoms) react with one another to form molecules of higher molecular weights. The initial molecules may be monomers or prepolymers; synthesis leads to polymers.

2. The right answer is hydrolysis.

Hydrolysis is a chemical reaction in which a covalent bond is broken by the action of a molecule of water.

For organic substances such as proteins, hydrolysis is equivalent to the cleavage of the peptide bonds between the different amino acids that constitute them.

Amino acids are cleaved by enzymes. So is the hydrolysis of starch or amylolysis, used in breweries or generally in the food industry to obtain glucose syrup.

3. The right answer is polymer.

The term polymer denotes a molecule of high molecular mass generally organic or semi-organic. A macromolecule consisting of a sequence of a large number of repeating units, one or more monomers, united to each other by covalent bonds.

Thus starch or proteins are polymers, just as silk or wood are made of polymers. Thermoplastics, thermosets and elastomers are also among the polymers. And polymer matrices are widely used in composite materials.

4. The right answer is lipid.

Lipids are the fat of living things. They are hydrophobic or amphiphilic molecules – hydrophilic molecules having a hydrophilic domain – very diversified, including among others fats, waxes, sterols, fat-soluble vitamins, mono-, di- and triglycerides, or even phospholipids.

5. The right answer is carbohydrate.

Carbohydrates are a class of organic compounds containing a carbonyl group (aldehyde or ketone) and at least two hydroxyl groups (-OH). Included in this class are substances derived from monosaccharides by reduction of the carbonyl group, by oxidation of at least one functional group at the end of the carboxylic acid chain or by replacement of one or more hydroxyl groups by an atom of hydrogen, an amino group, a thiol group or any similar atom.

6. The right answer is nucleic acid.

Nucleic acids are macromolecules, that is, relatively large, relatively complex molecules. They enter the family of biomolecules since they are of great importance in the realm of life, “bios” meaning life in Greek.

Nucleic acids are polymers whose base unit, or monomer, is the nucleotide. These nucleotides are linked by phosphodiester bonds.

7. The right answer is protein.

Proteins are fundamental materials of living matter. Most of our food contains it. From the biochemical point of view, these are large molecules made of chains of varying length of amino acids. All proteins, whether of bacterial, plant or animal origin, consist of a group of 20 amino acids.

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Scientists believe that the earth's early atmosphere lacked __________ gas because photosynthetic organisms did not yet exist. a hydrogen b nitrogen c oxygen d sulfur

Scientists believe that the earth’s early atmosphere lacked __________ gas because photosynthetic organisms did not yet exist. a hydrogen b nitrogen c oxygen d sulfur

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When the gases dihydrogen monosulfide and oxygen react, they form the gases sulfur dioxide and water vapor. Write the balanced chemical equation for the reaction.

Explanation:

An iron atom emits particles when it is struck by light.This phenomena is called as Photoelectric effect.

Photoelectric effect is defined as when photons (particles of light) falls on the metallic surface, electrons from the surface are ejected out and these ejected out electrons are called photo electrons.

This phenomena was not explained by John Dalton’s model of the atom.

Where as John Dalton’s model of atom explains that matter is made up smallest indivisible particle that is atom, elements combines in fixed proportion with another elements to give compounds, chemical reaction is an arrangement of an atoms.

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Which element, if combined with sulfur, will have the greatest attraction for the sulfur electrons? P Se I

Answer: Strontium (Sr) and Gallium (Ga) are the elements which have fewer than four dots in the electron dot diagrams.

Explanation: Electron dot diagrams are the diagrams which represent the valence electrons in an element. The electrons are represented by the dots in these diagrams.

Valence electrons in Arsenic (As) = 5

Valence electrons Strontium (Sr) = 2

Valence electrons in Krypton (Kr) = 8

Valence electrons in Gallium (Ga) = 3

Valence electrons in Tin (Sn) = 4

Valence electrons in Sulfur (S) = 6

Therefore, Strontium and Gallium are the elements having electron dots fewer than 4.

Electron Dot structures of these elements are given in the image attached.