can
someone please help

gao yin sheng, zhong yin sheng and the other shengs

There are seven oxygen atoms, so the total charge is −2⋅7=−14 . So, two chromium atoms have a total oxidation number of +12 . Since one is not more electronegative than the other, we can divide the number by two to get one chromium's oxidation number. So, a chromium atom here has an oxidation number of +6 .

Hope it helps you I'm from ph❤️

Answer:

Ionic compounds are formed from strong electrostatic interactions between ions, which result in higher melting points and electrical conductivity compared to covalent compounds. Covalent compounds have bonds where electrons are shared between atoms.

Answer:

Lithium, Magnesium, Zinc

Answer:

University of University of South New York Jersey has is a the best in the world the most important most important aspect of aspect of life is life and marriage is in my a lot more of a urban

Answer:

D. Something that splits up light into different colors

Explanation:

A prism separates light into various different colors. Thus, D is correct. :)

Answer:

Synthetic detergents can be used for washing purposes even when the water is hard, whereas soaps are not suitable for washing with hard water. This is because of the fact that synthetic detergents can lather with hard water. Hence, Synthetic detergents better than soaps.

Synthetic detergents work on both soft and hard water, while soap works only with soft water.

Answer:

D

Explanation:

Ionic bonds form when a metal and a nonmetal exchange electrons.

A) atoms with relatively similar electronegativities share electrons between them and form covalent bonds

B) the force that holds atoms together in a metallic substance is known as a metallic bond. such a solid consists of closely packed atoms....in short, the valence electrons in metals, unlike those of covalent bonds, are nonlocalized and capable of wandering relatively freely throughout the entire molecule

C) bonds formed between two nonmetals are mainly covalent bonds

.The characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.

Ionic or electrovalent bonds are bonds formed between oppositely charged ions which are formed by a gain or loss of electrons and these ions are held together by strong electrostatic forces of attraction.

Therefore, characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.

Learn more about ionic bonds at: https://brainly.com/question/13526463

My answer is in the picture.

Stay safe always

[tex]\huge\boxed{\boxed{\underline{\textsf{\textbf{Answer}}}}}[/tex]

⁺˚*･༓☾✧.* ☽༓･*˚⁺‧

⏩ The scattering of a beam of light through a colloidal solution in its dispersed phase is known as [tex]\large\boxed{tyndall \ \ effect}[/tex].

⁺˚*･༓☾✧.* ☽༓･*˚⁺‧

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐

Answer:

5 grams of iron react with 5 grams of oxygen to produce iron 3 oxide.

The actual yield of the reaction is--- 5 grams.

What is the percent yield?

Explanation:

The balanced chemical equation of the reaction is:

[tex]4Fe(s)+3O_{2} (g)->2Fe_{2} O_3(s)[/tex]

1)Identify the limiting reagent.

2)Using the limiting reagent calculate the amount of theoretical yield formed.

Identification of limiting reagent:

4 mol of Fe reacts with 3mol. of O2

that is:

4mol(55.84g/mol) of Fe reacts with ---- 3mol (32.0g/mol)

=223.36g of Fe reacts with ---- 96g. of O2

then,

5g of Fe requires how many grams of O2?

[tex]=>5g. of Fe * \frac{96g O2}{223.36g Fe} \\=2.14g. of O_{2} .\\[/tex]

But provided 5g of O2.

So, O2 is present more than required.

Hence, O2 is the excess reagent and the limiting reagent is Fe.

The amount of product formed depends only on the amount of Fe only.

Theoretical yield:

From the balanced chemical equation:

4mol. of Fe forms ----- 2mol. of Fe2O3.

that is

223.36g of Fe forms --- 2(159.68g)of Fe2O3.

=>223.36g of Fe forms --- 319.36g of Fe2O3.

then,

5g of Fe forms ----? grams of Fe2O3

[tex]=>5g of Fe * \frac{319.36g Fe2O3}{223.36g of Fe} \\=7.14g. of Fe2O3\\[/tex]

[tex]%Error =\frac{actual yield}{theoretical yield} * 100\\\\ %error=\frac{5g}{7.14g} * 100\\ %error =70.0[/tex]% error=actual yield/ theoretical yield  x 100

%error=5g./7.14g  x100

=>%error=70.0

Hence, the answer is 70.0%.

Answer:

HNO3 and NaOH

Explanation:

A neutralization reaction is a reaction that occurs between an acid and a base to form salt and water only.

Neutralization reactions are commonly carried out by method of titration. That is, a measured volume of acid of unknown concentration is made to react with a known volume of standard base solution or vice versa.

Two reactants that could be titrated to obtain sodium nitrate are nitric acid and sodium hydroxide.

The reaction equation is as follows;

HNO3(aq) + NaOH(aq) ----> NaNO3(aq) + H2O

Answer:

432

Explanation:

Answer:

4000mL

Explanation:

Using the combined gas law equation;

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (atm)

P2 = final pressure (atm)

V1 = initial volume (mL)

V2 = final volume (mL)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the information given in this question:

V1 = 1000mL

T1 = 20K

P1 = 1.0atm

V2 = ?

P2 = 0.5atm

T2 = 40K

Using P1V1/T1 = P2V2/T2

1 × 1000/20 = 0.5 × V2/40

1000/20 = 0.5V2/40

50 = 0.5V2/40

50 × 40 = 0.5V2

2000 = 0.5V2

V2 = 2000/0.5

V2 = 4000mL

Answer: The velocity of the first ball is 0.875 m/s if the second ball travels at 1.5 m/s after collision.

Explanation:

Given: [tex]m_{1}[/tex] = 0.2 kg,      [tex]m_{2}[/tex] = 0.15 kg

[tex]v_{1}[/tex] = 2 m/s,    [tex]v_{2}[/tex] = 0 m/s,      [tex]v'_{1}[/tex] = ?,          [tex]v'_{2}[/tex] = 1.5 m/s

Formula used is as follows.

[tex]m_{1}v_{1} + m_{2}v_{2} = m_{1}v'_{1} + m_{2}v'_{2}[/tex]

where,

v = velocity before collision

v' = velocity after collision

Substitute the values into above formula as follows.

[tex]m_{1}v_{1} + m_{2}v_{2} = m_{1}v'_{1} + m_{2}v'_{2}\\0.2 kg \times 2 m/s + 0.15 kg \times 0 m/s = 0.2 kg \times v'_{1} + 0.15 kg \times 1.5 m/s\\0.4 kg m/s + 0 = 0.2v'_{1} + 0.225 kg m/s\\0.2v'_{1} kg = 0.175 kg m/s\\v'_{1} = \frac{0.175 kg m/s}{0.2 kg}\\= 0.875 m/s[/tex]

Thus, we can conclude that the velocity of the first ball is 0.875 m/s if the second ball travels at 1.5 m/s after collision.

Answer:c

Explanation: it’s c

Answer:

B

Explanation:

hope the picture helps you to understand:)

Answer:

The nucleus is a small, region at the center of the atom which consists of protons and neutrons.

More Detailed Answer:

The nucleus is a small, dense region at the center of the atom. It consists of positive protons and neutral neutrons, so it has an overall positive charge. The nucleus is just a tiny part of the atom, but it contains virtually all of the atom's mass.

- flexbooks

Answer:

Rare earth elements are lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium - that appear in low concentrations in the ground.

Explanation:

The rare earth elements (REE) are a set of seventeen metallic elements. These include the fifteen lanthanides on the periodic table plus scandium and yttrium. Rare earth elements are an essential part of many high-tech devices.

Answer:

Explanation:

First of all, we need to understand what gravity is. Gravity in its simplest form can be best visualized as a force of attraction, that pulls all objects that have a mass towards itself.

It is usually exerted by an object with a larger mass and felt by objects with smaller masses.

Putting this into context, the earth exerts a gravitational pull on all substances with masses, which are around it. This includes the oceans, birds, airplanes, clouds, and even gasses in the atmosphere. The atmospheric gasses may be light enough to float, but they can't go very far, since gravity is constantly tugging at them. This keeps the gasses that make up our atmosphere, within a reasonable radius, which is very close to the earth. In a nutshell, gravity prevents them from floating away into outer space.

Answer:

Due to static charges.

Explanation:

In the illustration, we can see that when we bring the magnet close to the body, the static charges present on the body rearrange theirselves and attracted by the magnet. The magnetic substance is responsible for the arrangement of charges on the body and when they are arranged, they attract each other so we can say that static charges are present on the body and rearrangement occurs in the body.

Answer:urenium

Explanation: because his atomic number is 235

Answer:

We know when the no of protons (+ charge) is greater than the no of electrons (- charge), the nucleus pulls the electrons with greater force, hence making the size smaller. Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.

K has 19 protons, 19 electrons

K+ has 19 protons, 18 electrons

Ca has 20 protons, 20 electrons

Ca2+ has 20 protons, 18 electrons

Li has 3 protons, 3 electrons

Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.

Explanation:

Answer:

B. If they are inhaled or swallowed.

Answer:

The total energy, i.e. sum of kinetic and potential energy, is constant.

i.e. E = KE + PE

Initially, PE = 0 and KE = 1/2 mv^2

At maximum height, velocity=0, thus, KE = 0 and PE = mgh

Since, total energy is constant (KE converts to PE when the ball is rising),

therefore, KE = PE 

or, 1/2 mv^2 = mgh

or, h = v^2 /2g = 13^2 / (2x9.8) = 8.622 m

Hope this helps.

Answer:

The Lassaigne's test, also known as 

the sodium fusion test, is used in 

elemental analysis to determine the 

presenceof foreign elements,

 specifically halogens, nitrogen, and 

sulfur, in an organic compound.

--------------------------

☆Hope it helps

☆Have a great day!!

Answer:

It would be B!

Explanation:

Since white fur is a form of camouflage, B would be the correct answer.

IMK Your answer is option C

24 protons and 29 neutrons

Answer:

mice

bacteria

fungi

Explanation:

that's the answer