Can you please help me with this question

Answer:

"The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups."

Explanation:

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The ratio of H⁺ ions to OH⁻ ions at a pH = 2 is 10¹⁰

Given

ph = 2

Required

The concentration of H⁺ and OH⁻ ions

Solution

pH=-log[H⁺]

2=-log[H⁺]

[H⁺]=10⁻²

pH+pOH=14

pOH=14-2

pOH=12

pOH=-log[OH⁻]

12=-log[OH⁻]

[OH⁻]=10⁻¹²

[tex]\tt \dfrac{10^{-2}}{10^{-12}}=10^{10}[/tex]

Answer:

First one: 0.01

second one:  0.000000000001

third one: 10000000000

Answer:

Non-metals tend to gain electrons to attain Noble Gas configurations. The have relatively high Electron affinities and high Ionization energies. Metals tend to lose electrons and non-metals tend to gain electrons, so in reactions involving these two groups, there is electron transfer from the metal to the non-metal.

Answer:

Here is ur answer...

Explanation:

2) Half-filled d orbital increases the stability of the element.

Answer:

A

Explanation:

chemical reaction are those type of reaction that are irreversible and a new substance is being formed therefore when the iron combine with water and air it leads to rusting.

Answer:38°

Explanation:

Explanation:

When Henri Becquerel investigated the newly discovered X-rays in 1896, it led to studies of how uranium salts are affected by light. By accident, he discovered that uranium salts spontaneously emit a penetrating radiation that can be registered on a photographic plate.

Our Sun will eventually turn into a red giant in the cooler temperature and high luminosity and in the white dwarf phase has a hot temperature & dim luminosity.

In astronomy, the Hertzsprung-Russell diagram, often known as the H-R diagram, is a graph that plots the absolute magnitudes (intrinsic brightness) of stars against their spectral classifications (temperatures).

From the given diagram it is clear that when sun turns into a red giant then the temperature decreases and luminosity increases as it becomes large in size. And when it finally become a white dwarf then temperature comparatively increases and luminosity gets dim due to smaller size.

Hence in the red giant phase sun has a cooler temperature and high luminosity and in the white dwarf phase has a hot temperature & dim luminosity.

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Answer:

82.244%

Explanation:

The mass percent is an important method which is used to calculate the concentration of a solution. The mass percent of nitrogen in NH₃ is 82.2%.

The mass percentage of a particular component in a compound can be defined as the ratio of the mass of the particular component to the total mass of the compound.

The equation which is used to calculate the mass percentage is:

Mass percentage = Mass of the component / Total mass of the compound × 100

or

The mass percentage is also calculated as:

% Mass = Mass fraction × 100

Here the mass of 'N' = 14.00 g

The molar mass of NH₃ = 17.031 g/mol

% Mass of 'N' = 14.00 / 17.031 = 0.82

0.82 × 100 = 82.2 %

Thus the mass percentage of nitrogen is 82.2 %.

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Answer:

Nitrogen has an atomic number of 7 (Z=7) because it has 7 protons in its nucleus. Some nitrogen atoms have an atomic mass number of 15 (A=15). A is the number of neutrons plus protons in the nucleus. However, we already know that there are 7 protons

Answer:

Atomic number = Number of protons = Number of electrons

Atomic number = 7

Answer:

The evidence of matter scattering light wave in many different directions is;

D. The colors on the water's surface match the colors in the sky

Explanation:

Light scattering is used to describe the sending of a given beam of light in many directions (by tiny particles) when the light passes through a medium, due to the disruption of the bath of the light ray as it bumps into the tiny particles

Water has the nature of absorbing the red light. The light that enters the water is scattered by the tiny particles in the water such that the blue light which is the spectrum of light water allows to pass through is reflected along with the reflection of the sky and the colors of the water surface match the colors of the sky.

Answer:

C.

Explanation:

I took the quiz

Answer:

Metals transfers electrons to nonmetals. So K transfers one electron to Br because K is located at 1A in the periodic table. Br has seven electrons, now both K and Br are stable by gaining and losing one electron. The transfer of electrons makes metals to become positive ions and nonmetal to become negative ions. When an ionic bond is formed, the charges attract each other.

Answer: Metals transfers electrons to nonmetals. Potassium -K transfers one electron to bromine- Br because K is located in group 1A on periodic table. Br has seven electrons and located group 7A. Both K and Br stable by gaining and losing one electron. The transfer of electrons makes metals to become + positive ions and nonmetal to become - negative ions. An ionic bond is formed, the charges attract each other.

Explanation: Metals donate, or transfer, electrons to the nonmetal.

The transfer of electrons creates a positive ion and a negative ion.

An ionic bond is formed when the charges attract each other.

Answer:

metalloids

Explanation:

The kind of element most likely used to make semiconductors are the metalloids.

These elements have properties between those of metals and non-metals in that they are not truly metals and are partly non-metals.

Answer:

The answer is 46.0055. We assume you are converting between grams NO2 and mole. You can view more details on each measurement unit: molecular weight of NO2 or mol This compound is also known as Nitrogen Dioxide.

Explanation:

hope this helps

The volume did not change, it remained at 20 ml

Given

20 ml a sample gas at STP(273 K, 1 atm)

T₂=546 K

P₂=2 atm

Required

The volume

Solution

Combined gas Law :

[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]

Input the value :

[tex]\tt \dfrac{1\times 20}{273}=\dfrac{2\times V_2}{546}\\\\V_2=\dfrac{1\times 20\times 546}{273\times 2}\\\\V_2=20~ml[/tex]

The volume does not change because the pressure and temperature are increased by the same ratio as the initial conditions (to 2x)

Answer: Multiply the mass by the inverse of molar mass, and then multiply by Avogadro's number.

Explanation: Convert the mass to moles, multiply the number of moles by the ratio of the number of atoms or ions to one mole, multiply by Avogadro's number.

Answer:

D

Explanation:

Answer: C: The inner core is densest due to gravitational compression

Explanation:  

Answer:

a sea of electrons

Iron metal has a sea of electrons.

Iron metal is an element which possesses a sea of electrons as a result of it

containing cations which are usually surrounded by electrons which move at

a very fast pace .

This property makes Iron metal to be reactive when exposed to air( oxygen)

and it then forms various compounds such as Iron(II) oxide, Iron(III) oxide and

rust.

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P tot = 0.1065 atm

The mole fraction of oxygen in the mixture : 0.709

Given

10 L flask

1.013 g O₂

572 g CO₂

T = 18 °C = 291 K

Required

P O₂ and P CO₂

Solution

Dalton Law's of partila pressure

P tot = P₁ + P₂ + ..Pₙ

From ideal gas Law :

[tex]\tt P_{O_2}=\dfrac{\dfrac{1.013}{32}\times 0.082\times 291 }{10}\\\\P_{O_2}=0.0755~atm[/tex]

[tex]\tt P_{CO_2}=\dfrac{\dfrac{0.572}{44}\times 0.082\times 291}{10}\\\\P_{CO_2}=0.031~atm[/tex]

P tot = P O₂ + P CO₂

P tot = 0.0755 + 0.031

P tot = 0.1065 atm

The mole fraction of  O₂ :

[tex]\tt P_{O_2}=X_{O_2}\times P_{tot}\\\\X_{O_2}=\dfrac{P_{O_2}}{P_{tot}}\\\\X_{O_2}=\dfrac{0.0755~atm}{0.1065~atm}\\\\X_{O_2}=0.709[/tex]

Answer:

C: Something looking bent under water.

Answer:

0.00001= 1 x 10^-5. Since HCl is an acid, 1 x10^-5 is the H+ concentration. Write only the number of the exponent. Therefore, pH = 5.

Answer:

chemical structure determines the molecular geometry of ca compound by prtraying the arrangement of atoms and chemical bonds in the molecule..

Explanation:

hope this helps any <3

Answer:

O volume of the solution

Explanation:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / volume of solution  in L

For example:

if we dissolve the 1 mole of NaCl to make the solution of volume 2 L. The molarity of solution is,

M = 1 mol / 2 L

M = 0.5 M

Answer:

Chemical element, metallic, symbol Mg, situated in group IIa in the periodic table, atomic number: 12, atomic weight: 24,312. ... Magnesium is known for a long time as the lighter structural metal in the industry, due to it's low weight and to it's capability of forming mechanically resistant alloys.

Water boils when the vapour pressure is least the atmospheric pressure.

The atmospheric pressure is equal at the top of the mountain.

The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth.

As we go up in altitude the air pressure becomes less. When the pressure decreases, it takes less energy to get the water molecules to escape the surface. So the temperature is less than it would be at sea level.

Air pressure is higher or greater at the bottom of a mountain. This is because the height of the air above that level is thicker than at the top.

Pressure is given by the equation, P=rho*g*h, where rho is the air density, g is the gravity value and h is the thickness of the air layer on top of the level where we are considering the pressure.

Therefore, as we can see, at the bottom of the mountain, the thickness h of air is greater, and so is the pressure.

Hence, water boils when the vapour pressure is least the atmospheric pressure and the atmospheric pressure is equal at the top of the mountain.

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Answer:

It is Soluble

Explanation:

Name- Magnesium acetate

It dissolves easily in water and alcohol.

Heterogeneous, which means that they are not evenly combined.