I need help I don’t understand it and I need it done before the end of today

PbO  +  CO  →  Pb + CO₂

Oxidation States of the Elements

      Reactants     Products

Pb       +2                   0

O       -2, -2               -4

C         +2                 +4

Since the oxidation state/number of Pb decreased, it is being Reduced.

Since the oxidation state/number of C increased, it is being Oxidized.

Answer:

Number of Energy Levels: 4

First Energy Level: 2

Second Energy Level: 8

Third Energy Level: 14

Fourth Energy Level: 2

Explanation:

Hope It Helps!

Answer:

4 energy levels

Explanation:

1st energy level = 2 electrons

2nd energy level = 8 electrons

3rd energy level = 8 electrons

4th energy level = 8 electrons

Answer:

protons and electrons attract each other.

Explanation:

neutron as no charge,  proton and electron are exactly the same size but opposite. ( the opposite charge attract)

The protons possess a positive charge so they attract negatively charged electrons.

A proton can be described as a stable subatomic particle, a symbol with a positive charge of +1e elementary charge. Proton's mass is slightly less than that of a neutron but 1836 times the mass of an electron.

Protons and neutrons are jointly referred to as "nucleons" each with masses of approximately one atomic mass unit. More than one proton can be present in the nucleus of an atom. They give the attractive electrostatic central force which holds the atomic electrons.

The number of protons in the nucleus is referred to as the atomic number and is represented by the symbol Z. Since each element in the modern periodic table has a unique number of protons, its own unique atomic number, determines the chemical characteristics of the element.

As the neutrons are neutral do not carry any charge so the protons do not attract neutrons.

Learn more about protons, here:

https://brainly.com/question/12535427

#SPJ2

Explanation:

The molar mass of a compound can be calculated by finding the molar of the individual atoms that combine to make the compound.

Molar mass of compound =

         ∑ (molar mass of element × number of atoms of the element)

∴ Molar mass of dimethylglyoxime

                 = 4C + 8H + 2N + 2O

                 = [(4 × 12.011) + (8 × 1.0080) + (2 × 14.007) + (2 × 15.999)] g/mol

                 = 116.12 g/mol

answer: the variable part of an amino acid is the: SIDE CHAIN

The pH range of phenolphthalein is 8.3 - 10.0, which is suitable with the pH range of Strong Acid and Strong base titration and so phenolphthalein is used as a visual indicator in a strong acid-strong base titration.

Any substance that gives a clear visible indication of the presence or absence of a particular concentration of a chemical species, such as an acid or an alkali in a solution, usually by a colour change.

The pH range of Strong Acid and Strong base titration is 3–11 and equivalent point is at 7

the pH range of Strong Acid and Weak base  titration,  is 3–8 and equivalent point is below 7

the pH range of Weak Acid and Strong base  titration, is 6 - 11 and equivalent point is above 7

So for titration , an indicator with suitable pH range is used

The pH range of phenolphthalein is 8.3 - 10.0.

Therefore phenolphthalein is used as a visual indicator in a strong acid-strong base titration.

To know more about Indicator

https://brainly.com/question/12489874

#SPJ2

Answer:

Savory. Savory taste is caused by amino acids. It's commonly brought on by aspartic acid or glutamic acid. Occasionally, savory is also called “umami” or “meaty.”

Explanation:

Hope this helps.

Answer:

Mantle convection is the very slow creeping motion of Earth's solid silicate mantle caused by convection currents carrying heat from the interior to the planet's surface. The Earth's surface lithosphere rides atop the asthenosphere and the two form the components of the upper mantle.

I think it is helpful for you!!!!

Please make me brainliest..

Answer:

A group is a vertical row on the periodic table and a period is a horizontal row on the periodic table.

Explanation:

Answer:

A group on the periodic table refers to the vertical arrangement of the elements while a period refers to the horizontal rows of elements

Explanation:

To determine the molarity, we have to find the number of moles in the volume given, and then extrapolate to find the number of moles that would be in 1 L.

Determine the moles in the given volume

moles of LiCl = mass ÷ molar mass

                       = 139.9 g ÷ 42.39 g/mol

                       = 3.30 mol

Find the moles in 1 L

    Since 930 mL of LiCl    =   3.30 mol

    then 1000 mL of LiCl    =   (3.30 mol × 1000 mL/L) ÷ 930 mL

                                           =  3.55 mol/L

Answer:

147.28 cm³

Explanation:

Density = m/V

1.29 g = 190 g/cm3/V

V = 190 g/cm³ : 1.29 g

V = 147.28 cm³

Answer:

hi

Explanation:

Answer:

The shape of a covalent molecule can be predicted using the Valence Shell Electron Pair Repulsion (VSEPR) theory. Very simply, VSEPR theory says that the valence electron pairs in a molecule will arrange themselves around the central atom (s) of the molecule so that the repulsion between their negative charges is as small as possible.

Explanation:

There are two types of chemical compound one is covalent compound and another is ionic compound in chemistry. In ionic bonds, electrons are completely transferred. Electron-pair repulsion play an important role in determining the molecular shape using VSEPR theory.

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

The shape of a covalent molecule can be predicted using the Valence Shell Electron Pair Repulsion (VSEPR) theory.  VSEPR theory says that the valence electron pairs in a molecule will arrange themselves around the central atom (s) of the molecule so that the repulsion between their negative charges is as small as possible.

Therefore, electron-pair repulsion play an important role in determining the molecular shape using VSEPR theory.

To learn more about chemical compound, here:

https://brainly.com/question/26487468

#SPJ2

Answer:

Explanation:

Answer:

Most reactions occur quickly after ingestion or contact with the allergen, but some can occur up to a few hours later. There can also be a second phase of the reaction when symptoms reoccur. It is important to keep an eye on your child for about 6-8 hours following the first reaction.

Explanation:

Answer:

A- antimony

Explanation:

Answer:

A

Explanation:

Answer:

Elements in the same period have the same (number of electron shells)

The wavelength of the radiation whose frequency is 5 X 10^15s^-1 is 2.4 X 10^-6 inches, or 60 nanometers.

Answer:

Conditions that affect natural selection are reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.

Answer:

to create oxygen and energy in the form of sugar

Explanation:

photosynthesis is the process by which plants use sunlight, water, and carbon dioxide

The coefficient of oxygen is five which is needed to balance the given chemical equation and equation is C₃H₈ +5 O₂[tex]\rightarrow[/tex] 3 CO₂ +4   H₂O.

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

Learn more about chemical equation,here:

https://brainly.com/question/30087623

#SPJ7

A standard unit of measurement is a quantifiable language that helps everyone understand the association of the object with the measurement. It is expressed in inches, feet, and pounds, in the United States, and centimeters, meters, and kilograms in the metric system.

Answer: Scientists work independently to form theories about the Earth without sharing d

Scientists work independently to form theories about the Earth without sharing data.

Solar system is defined as the grouping of the eight planets and their moons in orbit around the sun, as well as other smaller bodies like comets, asteroids, and meteoroids.

It can also be defined as the Sun's orbiting objects are confined by gravity to one system.

An orbiting collection of planets, meteors, or other celestial bodies is referred to as a star system.
The Sun, an ordinary star, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto make up our solar system.

Our solar system is referred to as the "solar system" because our Sun is called Sol after the Latin word for Sun, "solis," and because anything related to the Sun is termed "solar."

Thus, scientists work independently to form theories about the Earth without sharing data.

To learn more about solar system, refer to the link below:

https://brainly.com/question/12075871

#SPJ2

Answer:

6 Electrons r smaller than a proton or a neutron

Answer:

1st and last one

Explanation:

Answer:

because of the reflection that the Sun makes on the water after it rained.

bởi vì sự phản chiếu mà mặt trời tạo ra trên mặt nước sau khi trời mưa

Explanation:

Answer:

0.225 L = 225 mL

Explanation:

Charles' Law states that for a fixed pressure, the volume is directly proportional to the temperature, which means things expand at the same rate as the rate of it being heated up

Mathematically, we can write that as:

V1/T1 = V2/T2, where 1 and 2 are the two situations

So, when we substitute the values in, we get:

0.25 L/298 K = V2/268 K

Rearranging this, we get:

(0.25/298) x 268 = 0.225 L = 225 mL.

This also makes sense, as the volume reduced a little when the temperature reduced (cooled down)

Let me know if this makes sense, and hope I helped! :)

Answer:

ionic

Explanation:

Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white

Answer:

p orbital

Explanation:

Answer:

what do you mean?

Explanation:

Studying the brightness of a star can indeed help scientists determine what part of the life-cycle a star is in. The brightness of a star is directly related to its stage in the life cycle.The statement is true.

During the early stages of a star's life, it is formed from a cloud of gas and dust. As the star contracts under its own gravity, it starts to heat up and emits light. This is known as the protostar stage.

As the star continues to contract, it reaches a point where the core temperature becomes hot enough for nuclear fusion to occur. At this stage, the star enters the main sequence phase, where it will spend the majority of its life. The brightness of the star in this phase is determined by its mass. More massive stars are brighter than less massive ones.

As the star ages, it exhausts its hydrogen fuel in the core and begins to evolve. Depending on its mass, a star can become a red giant, a white dwarf, a neutron star, or even a black hole. Each of these stages has a different brightness profile.

By observing the brightness of a star over time, scientists can gather information about its age, mass, and evolutionary stage. This can provide insights into the star's life cycle and help in understanding the processes occurring within it.

Thus, studying the brightness of a star is an important tool for scientists to determine what part of the life cycle a star is in. By analyzing its brightness profile, scientists can gain valuable information about the star's age, mass, and evolutionary stage.The statement is true.

Learn more about star,here:

https://brainly.com/question/31987999

#SPJ3

Answer:

I,II and III

Explanation:

Hope this helps :)

Answer:

l and III is the answer.

hope it hepls