Which temperature is coldest??

Answer: A

Explanation: USATestPrep

Final answer:

Catalase is used by the body to quickly decompose hydrogen peroxide into water and oxygen. In a lab, this process can be accelerated using catalysts like manganese (IV) oxide or iodide ion, which lower the activation energy and speed up the reaction without being consumed.

Explanation:

Hydrogen peroxide (H₂O₂) is a reactive oxygen species and a byproduct of aerobic metabolism, which can be harmful to cells by causing damage to DNA, proteins, and lipids. To prevent cellular damage, the body uses an enzyme called catalase to facilitate the rapid decomposition of hydrogen peroxide into water (H₂O) and oxygen (O₂). Additionally, the process can be sped up in a laboratory setting by using a catalyst, such as manganese (IV) oxide or iodide ion, which provides an alternate reaction pathway with a lower activation energy, enhancing the reaction rate without being consumed by the reaction itself.

The catalytic decomposition of hydrogen peroxide is crucial both biologically, to protect living organisms from oxidative damage, and chemically, in applications ranging from disinfection to industrial processes. By using catalase or other catalysts, hydrogen peroxide is efficiently broken down, thus eliminating the threat posed by this potent oxidant.

To determine unpaired electrons, look at the valence electrons in an ion's molecule, accounting for extra or absent electrons due to the ion's charge. For instance, O2- and F2+ have one unpaired electron, but N22- is not a valid ion, and O22- electrons are all paired.

To determine if a molecular ion will have one or more unpaired electrons, we need to look at the number of valence electrons in the molecule and take into account any extra or absent electrons due to the charge of the ion.

For example, O2- has 12 + 1 = 13 valence electrons (6 from each oxygen atom and 1 extra due to the negative charge). It requires 14 for all the electrons to be paired (2 in each oxygen's inner shell and 4 bonds or lone pairs in the outer shell), thus there is one unpaired electron in O2-.

However, in F2+, there are only 13 electrons because one electron is lost due to the positive charge. Like oxygen, fluorine also prefers to have 7 electrons in its outer shell, so there are also unpaired electrons in F2+.

N22- doesn’t exist because nitrogen normally forms triple bond and doesn’t need or want to take extra electrons, so this molecular ion is not valid.

O22- has 14 + 2 = 16 valence electrons and this total number of valence electrons is an even number, which indicates all the electrons are paired.

https://brainly.com/question/29656941

#SPJ3

Answer: Oxidation state of chlorine in the given compound is +7.

Explanation:

Oxidation state is defined as the number which is assigned to the element when it gains or loose electrons. If the element gains electron, it will attain a negative oxidation state and if the element looses electrons, it will attain a positive oxidation state.

We take the oxidation state of chlorine atom be 'x'.

Oxidation state of sodium atom = +1

Oxidation state of oxygen atom = -2

Evaluating the oxidation state of chlorine atom:

[tex]+1+x+4(-2)=0\\\\x=+7[/tex]

Hence, the oxidation state of chlorine in the given compound is +7.

In the given question, the oxidation number of chlorine (Cl) in [tex]\rm NaClO_4[/tex] is +7.

The oxidation number of an atom is defined as the charge that atom would have if all the shared electrons in the bonds were assigned to the more electronegative atom in the bond.

In  [tex]\rm NaClO_4[/tex], sodium (Na) has an oxidation number of +1 and oxygen (O) has an oxidation number of -2. The overall charge of the compound is -1, which means that the sum of the oxidation numbers of all the atoms in the compound must equal -1.

Let x be the oxidation number of chlorine. Then we have:

[tex](+1) + x + 4(-2) = -1[/tex]

Simplifying the equation, we get:

[tex]+1 + x - 8 = -1[/tex]

[tex]x - 7 = -1[/tex]

[tex]x = +7[/tex]

Therefore, the oxidation number of chlorine in  [tex]\rm NaClO_4[/tex] is +7.

Learn more about oxidation number here:

https://brainly.com/question/29263066

#SPJ6

Answer:

For 1: The correct answer is Option D.

For 2: The correct answer is Option B.

For 3: The correct answer is Option A.

Explanation:

For 1:

An ion is formed when a neutral atom looses or gains electrons.

We are given:

An ion carrying a charge of +3. This means that an element is loosing 3 electrons, so it has 3 valence electrons.

The elements that belong to Group 13 of the periodic table has 3 valence electrons and form +3 ions.

Hence, the correct answer is Option D.

For the given options:

Option A: Covalent bond is defined as the bond which is formed when sharing of electrons takes place between the atoms. This is usually formed between two non-metals.

Option B: Ionic bond is defined as the bond which is formed by complete transfer of electrons from one atom to another atom. The atom which looses the electron is known as electropositive atom and the atom which gains the electron is known as electronegative atom. This bond is usually formed between a metal and a non-metal.

Option C: A polar covalent bond is formed when difference in electronegativity between the atoms is present. When atoms of different elements combine, it results in the formation of polar covalent bond. For Example: [tex]CO_2,NO_2[/tex] etc..

Option D: Hydrogen bonding is defined as the intermolecular force having partial ionic-covalent character. This type of bonding takes place between a hydrogen atom (attached with an electronegative atom e.g. O, N and F) and an electronegative atom (O,N and F).

Group 2 elements are considered as metals having general electronic configuration as [tex]ns^2[/tex]

They will loose 2 electrons to form [tex]X^{2+}[/tex] ions and thus tends to form ionic bonds.

Hence, the correct answer is Option B.

When a positive ion gains electrons equal to the charge on the ion, the positive charge will get neutralized by the negative charge.

[tex]X^{2+}+2e^-\rightarrow X[/tex]

The ion will loose its charge and will form a neutral atom.

Hence, the correct answer is Option A.

Answer: ice cubes, paper

Explanation:

Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Iron [tex]Fe[/tex], Aluminium [tex]Al[/tex]

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions.

Example: ice cubes [tex]H_2O[/tex] , paper which is made of cellulose [tex]C_6H_{10}O_5)_n[/tex]

Thus ice cubes and paper are compounds.

Hello, the correct answer to your question is, D.  boiling and melting

I hope this helped!

Final answer:

To prepare a solution, use the formula: amount of solute = volume of solution x concentration of solute. For a 50.0 mL solution with a concentration of 5.0%, you would need 2.5 g of solute. For a 1250 mL solution with a concentration of 4.0%, you would need 50.0 g of solute.

Explanation:

To calculate the amount of solute needed to prepare a solution, we need to use the formula:

Amount of solute = volume of solution x concentration of solute

Using this formula:

a) For a 50.0 mL solution with a concentration of 5.0%, the amount of solute needed is:

Amount of solute = 50.0 mL x 5.0% = 2.5 g

b) For a 1250 mL solution with a concentration of 4.0%, the amount of solute needed is:

Amount of solute = 1250 mL x 4.0% = 50.0 g

Answer: 18 = Mass umber

8 = atomic number

Explanation:

An atom is smallest unit of a matter or substance.It consist of three subatomic particles : electrons, protons, neutrons.

Protons and neutrons are located in the center of an atom where while mass of an atom is concentrated.

Mass number = Number of protons + Number of neutrons

Atomic number = Number of protons = Number of electrons (for a neutral atom)

General representation of an element is given as: [tex]_Z^A\textrm{X}[/tex]

where,

Z represents Atomic number

A represents Mass number  

X represents the symbol of an element

Oxygen is the 8th element of the periodic table and is written as [tex]_8^{16}\textrm{O}[/tex], thus 8 = atomic number and 18= Mass number

Answer : The number of neutrons in an atom U-233 is, 141 neutrons.

Explanation :

The given atom is, U-233

The atomic mass number of U = 233

The atomic number of U = 92          (from the periodic table)

Now we have to determine the number of neutrons in U-233.

Number of neutrons = Atomic mass number - Atomic number

Number of neutrons = 233 - 92 = 141

Therefore, the number of neutrons in an atom U-233 is, 141 neutrons

Answer:

Option (A)

Explanation:

The asthenosphere is the upper part of the mantle and this region is just below the lithosphere. The lithospheric plates are divided into 2 types, namely the continental crust and the oceanic crust. These plates moves over this layer of asthenosphere due to the generation of the convection current in the mantle. This currents also forces the asthenosphere to move considerably at a slower rate. This convection current is formed due to the heat radiated from the core (interior) of the earth. The core of the earth is comprised of the denser and molten rocks such as iron and nickel. The rocks in the asthenosphere are solid in nature, but they have the ability to move during deformation.

Hence, the correct answer is option (A).

The statement is false. The introduction of harmful agents into water that degrade its quality is known as water pollution, not geo-pollution.

The statement provided in your question, "The introduction of chemical, physical, and/or biological agents into water that degrade the water quality is known as geo-pollution," is false. The correct term for this phenomenon is water pollution. Water pollution occurs when harmful substances, often chemicals and microorganisms, contaminate a body of water, rendering it harmful to the organisms that rely on it. Geo-pollution, on the other hand, refers more broadly to pollution of the Earth's geosphere, which includes the lithosphere, hydrosphere, and atmosphere.

https://brainly.com/question/19920929

#SPJ3

Answer:

The isotope must have 31 electrons

Explanation:

Answer:  Studying atoms is important because knowledge about atoms helps people to understand the world around them and produce materials used in daily life. Also, research done on atoms has contributed to the improvement of people's lives through medicine, to the protection of the environment, and to the discovery of new things about the world and the universe.

Answer: Amino acid

Explanation:

Amino acid is a monomer that combines together to form a polymer known as protein. Two or more than two amino acids combine to form a protein.

The amino acids are joined together by peptide bond. Amino acids are the most important and basic components of life that performs the vital functions of the body.

A chemical reaction can form products which are new substances differing from the initial reactants. These chemical changes lead to formation of different types of matter. Examples include formation of water from hydrogen and oxygen, and creating table salt from Sodium and Chloride ions.

Products can form as a result of a chemical reaction. A chemical reaction occurs when two or more atoms bond together to form molecules or when bonded atoms break apart. The substances used in a chemical reaction are known as reactants and the substances produced are known as the products. For instance, if hydrogen (H) reacts with oxygen (O), it can form water (H₂O).

Chemical changes also result in formation of one or more types of matter that differ from the matter present before the change. For instance, the formation of rust is a chemical change because rust is different from the iron, oxygen, and water that were there before rust formed. Similarly, the explosion of nitroglycerin is a chemical reaction because the gases produced are very different from the original substance.

Additionally, chemical reactions can create new substances as products. For instance, Sodium and Chloride ions are the reactants in the production of table salt, with table salt being the product.

https://brainly.com/question/34137415

#SPJ6

The correct answer is Seafloor Spreading

Give me brainliest if it is correct!

The theoretical yield of carbon dioxide can be calculated using the stoichiometric ratio in the balanced equation for the reaction. It is the amount of product that would be obtained if all reactants were completely converted to product under ideal conditions. The theoretical yield can be calculated by multiplying the amount of the starting reactant by the stoichiometric ratio in the balanced equation.

Theoretical yield is the amount of product that would be obtained from a chemical reaction if the reaction proceeded perfectly and all reactants were completely converted to product. In this case, the balanced equation shows that 1 mole of H3C6H5O7 reacts with 3 moles of NaHCO3 to produce 3 moles of CO2. Therefore, the theoretical yield of carbon dioxide would be 3 times the amount of H3C6H5O7 given.

Example: If 2 moles of H3C6H5O7 are given, the theoretical yield of CO2 would be 3 x 2 = 6 moles.

Note that the theoretical yield assumes ideal conditions and perfect conversion, so the actual yield may be less due to factors like incomplete reactions or side reactions.

https://brainly.com/question/23123430

#SPJ2

Explanation:

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

First calculate the number of valence electrons in [tex]N_2O_3[/tex] is 28.

The lewis structure of [tex]N_2O_3[/tex] is given in an image.

The term "Lewis structure" refers to a diagram used to represent the bonding and electron distribution in a molecule or ion. It was developed by American chemist Gilbert N. Lewis.

Step 1: Count the total number of valence electrons.

N2O3 consists of two nitrogen atoms (N) and three oxygen atoms (O). Nitrogen is in Group 15 of the periodic table and has 5 valence electrons, while oxygen is in Group 16 and has 6 valence electrons. Therefore, the total number of valence electrons in N2O3 can be calculated as follows:

(2 × 5) + (3 × 6) = 10 + 18 = 28 valence electrons

Step 2: Determine the central atom.

In N2O3, nitrogen (N) is the central atom because it is the least electronegative element in the compound.

Step 3: Connect the outer atoms to the central atom.

In N2O3, each oxygen (O) atom will be bonded to the central nitrogen (N) atom. This will form a single bond between each oxygen and the nitrogen atom.

Step 4: Distribute the remaining electrons.

After forming the single bonds, we subtract the number of electrons used from the total valence electrons calculated in step 1. In this case, we have used 8 electrons (4 electrons for the two N-O single bonds).

Remaining electrons = Total valence electrons - Electrons used in bonds

Remaining electrons = 28 - 8 = 20 electrons

Step 5: Distribute the remaining electrons around the outer atoms.

Since each oxygen atom is bonded to the central nitrogen atom, we distribute the remaining 20 electrons evenly around the oxygen atoms (8 electrons for each oxygen).

Step 6: Check the octet rule and adjust if necessary.

After distributing the remaining electrons, we check if all atoms have achieved an octet (except for hydrogen, which can have a duet). In N2O3, the oxygen atoms already have an octet (8 electrons), but the nitrogen atom has only 6 electrons. To complete the octet of the nitrogen atom, we can use one pair of electrons from the adjacent oxygen atom to form a double bond between nitrogen and oxygen.

Step 7: Check the octet rule again and adjust if necessary.

After forming the double bond, all atoms in N2O3 have achieved an octet, and we have used all 28 valence electrons.

Learn more about Lewis Structure here:

https://brainly.com/question/20300458

#SPJ2

The correct pairing of a chemical name with its formula from the given options is 2.N2O5, which is named dinotrogen pentoxide.

Of the given options, 2.N2O5 dinotrogen pentoxide is correctly paired with its name. The chemical name for MgCl2 is magnesium chloride, not magnesium dichloride. Similarly, H20 should be written as H2O and it is correctly named water or dihydrogen monoxide, not hydrogen oxide. Lastly, CuCl2 is copper (II) chloride, not copper (III) chloride, because copper in this compound has a +2 oxidation state, not +3.

Answer:

All the three phases coexist at triple point.

Explanation:

The triple point of water is 0.01°C (273.16K) and 4.58 mmHg. At this temperature and pressure the water exist in all the three forms or phases.

The three phases are solid, liquid and gas.

It is like water is boiling and freezing at the same time.

If we change temperature or pressure, even slightly, one of the phases of water will disappear (based on changes made).

Answer:

B. Chlorine

Explanation: