Please I need help ASAP . I will mark brainliest​

Answer:

D

Explanation:

its just right

Answer:Reactants combine to form Products. Hope this helped! ;)

Explanation:

Answer:

1. 2Mg + O2 —> 2MgO

2. 2H2 + O2 —> 2H2O

3. CH4 + 2O2 —> CO2 + 2H2O

Explanation:

1. Magnesium + Oxygen —> Magnesium Oxide

Mg + O2 —> MgO

There are 2 atoms of O on the left side and 1 atom on the right side. It can be balance by putting 2 in front of MgO as shown below:

Mg + O2 —> 2MgO

There are 2 atoms of Mg on the right side and 1 atom on the left side. It can be balance by putting 2 in front of Mg as shown below:

2Mg + O2 —> 2MgO

Now the equation is balanced.

2. Hydrogen + Oxygen —> Water

H2 + O2 —> H2O

There are 2 atoms of O on the left side and 1 atom on the right side. It can be balance by putting 2 in front of H2O as shown below:

H2 + O2 —> 2H2O

There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by putting 2 in front of H2 as shown below:

2H2 + O2 —> 2H2O

Now, the equation is balanced.

3. Methane + oxygen à Carbon dioxide + Water

CH4 + O2 —> CO2 + H2O

There are 4 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 2 in front of H2O as shown below:

CH4 + O2 —> CO2 + 2H2O

There are 2 atoms of O on the left side and a total of 4 atoms on the right side. It can be balance by putting 2 in front of O2 as shown below:

CH4 + 2O2 —> CO2 + 2H2O

Now, the equation is balanced.

Answer:

See explanation

Explanation:

We must remember that gases exhibit ideal gas behavior at ordinary temperature and pressure.

As the system approaches absolute zero gas laws begin to break down and the relationship linear  between volume and temperature (Charles law is broken).

Recall that, at absolute zero, the volume of an ideal gas would be zero and all molecular motion stops due to the fall in temperature and kinetic energy of the molecules.

The reason for linear should be explained below.

Since the system approaches absolute zero gas laws starts to break down and the relationship is linear  between volume and temperature  At absolute zero, the volume of an ideal gas should be zero and all molecular motion stops because to the fall in temperature and kinetic energy of the molecules.

Learn more about the temperature here: https://brainly.com/question/19258620

Answer:

gas

Explanation:

it would evaporate

Answer:

There will be no new land for the plant and other organisms or resources.

Explanation:

The Mid-Atlantic ridge is one of the seafloor expanding which is a process in which due to the presence of magma or lava a pressure form under the seafloor or seabed that two plates moving away from one another.

The gap between these plates is filled with lava which leads to the formation of new rocks and land after cooling down, which provides soil, nutrients for the various resources, and leads to new biodiversity. If there will be no land formation there will be no new resources or the ecosystem will be there.

Answer:

I'm between B, C, and D

Explanation:

Becasue all of them can become in a chemical change but what is thing is that B or C will be the ones because they can turn into something will the lighting strike won't turn the Tree into something the tree will stay the same

Answer:

High melting and boiling points and therefore solid at room temperature

A crystalline structure

Ability to dissolve easily in water

Ability to conduct electricity well

Explanation:

The hypothesis mentioned in the question will be something like this

'If a substance is solid at room temperature, has a crystalline structure, dissolves easily in water, and conducts electricity well, then it likely contains ionic bonds. Otherwise, it likely contains covalent bonds'

We can see that all the items selected in the answer box were included in the hypothesis.

Answer:

C, B, D

good luck on your Chem!

comment if you have any questions!

Answer:  Disdain

Explanation: Deborah believes that people of other nationalities are inferior to her. she treats them with disdain and does not miss an opportunity to abuse them.

Answer:

0.578 mol H₂SO₄

Explanation:[tex]\frac{3.48 * 10^{23}H2SO4}{1}[/tex] ×[tex]\frac{1 mol H2SO4}{6.02214*10^{23}molecules H2SO4}[/tex] =0.5778 mol H₂SO₄ = 0.578mol H₂SO₄

Answer: They are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr)

Explanation: Have a great day-

Answer:

Lithium

Explanation:

Ap3x

Answer:4

Explanation:

Answer:

c.4 Just took the test!!!

Explanation:

Answer:

Osmosis is the movement of solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution. ... Diffusion: Diffusion is the movement of particles from an area of higher concentration to lower concentration. The overall effect is to equalize concentration throughout the medium.

Answer:

Explanation:

It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities. ... Calcium reacts with fluorine to form the compound CaF2. ... (lead is very close) as hydrogen the bond would be considered ionic! ... What is the most stable monatomic ion formed from nitrogen?

Answer:

CaF2 is stable when it is formed because Ca loses two of its electrons. Both accept one electron each. now the Calcium is satisfied because it lost its two electrons and is now behaving like a noble gas, which is what they all want to be like The Flourine is satisfied because they both gained one electron, allowing them to have 8 valence electrons also like a noble gas.

The key is in the 8 valence electrons! Ca has to lose two to have 8, and F has to gain one to have 8fluorinefluorines...

Explanation:

Chemical and mechanical energy is involved after a car is filled with gasoline and driven down the road. So the correct options are A and C.

Chemical energy is the energy that is stored in the bonds of any chemical compound. The chemical energy can be released when a chemical reaction is occurring, most commonly in the form of heat. These kinds of reactions are called exothermic reactions.

The reactions that need an input of heat energy to proceed and that may store an amount of that energy as chemical energy in their newly synthesized bonds are called endothermic reactions.

For example, the chemical energy in food is converted into mechanical energy and heat energy in the body.

Mechanical energy is defined as the sum of kinetic energy and potential energy. Kinetic energy is the energy of motion and potential energy is the energy stored in a system because of the position of its parts.

In a system that has only gravitational forces, mechanical energy is constant. This is an otherwise idealized system. This means that this lacks dissipative forces like forces of friction and of air resistance.

Therefore the correct options are A and C.

Read more about chemical and mechanical energy, here

https://brainly.com/question/13552918

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Explanation:

Like all EM waves, light transports energy across space. The intensity (energy per unit area and unit time) is proportional to the square of the amplitude of the electric field of the light wave. This energy, however, arrives at a receiver not continuously but in discrete units called photons. The energy transported by an electromagnetic wave is not continuously distributed over the wave front. It is transported in discrete packages. Photons are the particles of light.

Properties of photons:

Photons always move with the speed of light.

Photons are electrically neutral.

Photons have no mass, but they have energy E = hf = hc/λ. Here h = 6.626*10-34 Js is a universal constant called Planck's constant. The energy of each photon is inversely proportional to the wavelength of the associated EM wave. The shorter the wavelength, the more energetic is the photon, the longer the wavelength, the less energetic is the photon.

A laser beam and a microwave beam can carry the same amount of energy. In this case the laser beam contains a smaller number of photons, but each photon in the laser beam has a higher energy than the photons in the microwave beam.

Photons can be created and destroyed. When a source emits EM waves, photons are created. When photons encounter matter, they may be absorbed and transfer their energy to the atoms and molecules. Creation and destruction of photons must conserve energy and momentum. The magnitude of the momentum of a photon is p = hf/c = h/λ.

Problem:

What is the energy of a photon of blue light (λ = 450 nm) and of a photon of red light (λ = 700 nm) in units of eV = 1.6*10-19 J?

Solution:

E = hc/λ.

Blue light: E = (6.626*10-34 Js)(3*108 m/s)/(450*10-9 m) = 4.4*10-19 J = 2.76 eV

Red light: E = (6.626*10-34 Js)(3*108 m/s)/(700*10-9 m) = 2.8*10-19 J = 1.8 eV

Problem:

A 100-W incandescent light bulb uses 100 W (100 W = 100 J/s) of electrical power but only radiates about 15 W of actual visible light. Roughly how many visible photons per second hit the open pages of a typical hardcover book if the pages are about 2 m from the bulb and face it directly?

Solution:

We have to make a variety of estimations and approximations to solve this problem.

To find the number of photons hitting the pages each second, we have to know the light energy hitting the pages per second and the energy per photon. We could compute the latter if we knew the wavelength of the light, but the visible light emitted by a normal incandescent bulb is a mix of wavelengths.

Let us estimate that the average wavelength of the visible light is about 550 nm, which is in the yellow region of the spectrum. This means that the average energy per photon is about

E = hc/λ = (6.626*10-34 Js)(3*108 m/s)/(550*10-9 m) = 3.61*10-19 J = 2.26 eV.

To find the number of photons hitting the pages of a book, we need to know the energy per second that falls on the pages. Let us assume that the light energy from the bulb travels uniformly in all directions. Imagine a sphere centered on the light bulb with a radius R = 2 m. Every second, 15 J or so of visible light energy crosses this sphere. If the light energy is spread uniformly over the sphere, then the intensity of the visible light or the energy per unit area per unit time in units of W/m2 at any point on the inner surface of the sphere will be

I = Plamp/(4πR2),

Electrons are ejected from a metal surface with speeds ranging up to 4.6*105 m/s when light with a wavelength of 625 nm is used.

(a) What is the work function of the surface?

(b) What is the cutoff frequency of the surface?

Answer:

Single Replacement

Explanation:

Synthesis Reactions:

A + B → AB

Combustion Reactions:

CₓHₐ + O₂ → CO₂ + H₂O

Double Replacement Reactions:

AB + CD → AD + CB

Single Replacement Reactions:

A + BC → AB + C

Given RxN: 2Al + 3FeO → Al₂O₃ + 3Fe

Answer:

P=1.50 g/mL

this is the answer☺

Hop it helps you!

Answer:

-Electrons are delocalized in a "sea of electrons" and are shared among the positively charged metal ions.

Explanation:

In a metallic bond, electrons are delocalized in a sea of electrons and are shared among the positively charged metal ions.

- In a metallic bond, there is delocalization of electrons. The electrons are shared in between the atoms, rather than getting transferred. So, there is no transfer of electrons.

- The electrons are delocalized and shared alongside the nuclei of the atom. There is no existence of electrons around the neutral atoms.

- In the metallic bonds electrons are delocalized and are shared among the positively charged atomic nuclei in the form of a sea of electrons. Thus, electrons are delocalized in a sea of electrons and are shared among positively charged metal ions.

- There is an equal sharing of electrons in the bond. No unequal and partial sharing is there.

For more information about the metallic bond, please refer the link:

https://brainly.com/question/2890161?referrer=searchResults

Answer:

Explanation:

Sleet and freezing rain occur under very similar conditions. Sleet is pellets of ice that form when snow falls into a warm layer and melts into rain. The rain then falls into a freezing layer of air that is deep enough to refreeze the raindrops into pellets.

Answer:

carbon-12 (12C) and carbon-13 (13C).

nitrogen-14 (14N) and nitrogen-15 (15N)

omg im so dumb i cant answer this question omg sorry im 302918291802832908310 years old and i cant think propertly

Answer:

James Chadwick

Explanation: By 1920, physicists knew that most of the mass of the atom was located in a nucleus at its center, and that this central core contained protons. In May 1932 James Chadwick announced that the core also contained a new uncharged particle, which he called the neutron.

Answer:

eon,era, period

Explanation:

Answer:

period<era<eon

Explanation:

I took the test, sadly got a 70%.

Answer:

1.0 g/cm3

Explanation:

Water behaves anomalously since it contracts when cooled from any temperature until 4°C and begins to expand below this temperature. Thus water expands when cooled between 4°C to 0°C.

It then follows that water has its maximum density at 4°C. The maximum density of water is 1.0 g/cm3. This is the density of water at 4°C.

Explanation:

A student measures the length of a magnesium ribbon three times and records the data as: (a). 23.486 cm, (b). 23.491 cm, (c). 23.511 cm

The labeled value of the magnesium ribbon is 23.490 cm

We need to find the precent error for all the data recorded by the student.

[tex]\text{Percentage error} = \dfrac{|\text{calculated value-actual value}|}{\text{acutal value}}\times 100[/tex]

(a) When the calculated value = 23.486 cm

[tex]\text{Percentage error} = \dfrac{23.486 -23.490 }{23.490 }\times 100\\\\=0.017\%[/tex]

(b) When the calculated value = 23.491 cm

[tex]\text{Percentage error} = \dfrac{23.491 -23.490 }{23.490 }\times 100\\\\=0.0042\%[/tex]

(c) When the calculated value = 23.511 cm

[tex]\text{Percentage error} = \dfrac{23.511 -23.490 }{23.490 }\times 100\\\\=0.0893\%[/tex]

When the calculated value is 23.486 cm, it has least error of 0.017%.

Answer:

Nobody cares

Explanation:

Cause nobody cares hope this helps

Answer:

C

Explanation:

The valence electrons should be the ones reacting

Answer:

Only electrons in the outermost shell can participate in chemical reactions!

Explanation: