help meeeeeeeeeeeeee​

Answer:

2Na2S + Cd(NO3)2 ---> CdS + 2NaNO3

The coefficients therefore are 1,1,1&2

"" ANSWER""

Protons are values ​​of atomic numbers that do NOT change, that is, they are located inside the nucleus of the atom, whereas electrons are located in the electrosphere that can gain or lose electrons, the electron has a negative charge and the Proton positive, that is, if in any atom it wins an electron the atom will be negative and if the atom loses it will be positive because we already know that the number of protons does not change. To calculate the number of neutron we have to make the number of rounded atomic mass which becomes mass less the number of protons for example oxygen gas has 8 protons which is the atomic number and has atomic mass 15,999 which rounding up to 16 to find the number of neutrals we do 16-8 = 8 so now we know that oxygen has: 8 protons, 8 electrons and 8 neutrons but the values ​​will not always be the same but the possibility of protons and neutrals having the same value is 75% by my count .

● ○ ● RULES ○ ● ○ ●

Atomic number = number of protons

Atomic mass ROUNDNESS = mass

Number of neutrons = number of protons - mass number

OBSERVATION- EXPLANATION FOR STUDENTS OF 9 YEARS BECAUSE IN THE HIGH SCHOOL UP SOME CHANGES CHANGE.

■■ GOOD STUDIES ■■

Answer:

Refer to attached file below

Hope it helps..

Have a great day :P

Answer:

Partial pressure of O₂ =  228 mmHg

Explanation:

The mixture is made of three gases, He, N₂ and O₂.

Total pressure of it, is 781 mmHg.

There is a law from gases, that indicates the sum of partial pressures of each gas in a mixture will be the total pressure of the system. In conclussion:

Partial pressure of He + Partial pressure of N₂ + Partial pressure of O₂ = Total pressure.

331 mmHg + 222 mmHg + Partial pressure of O₂ = 781 mmHg.

Partial pressure of O₂ = 781 mmHg - 331 mmHg - 222 mmHg

Partial pressure of O₂ =  228 mmHg

Answer:

See explanation

Explanation:

When either pan is heated, energy is transferred via conduction. Conduction is the process by which heat is transferred through a material, the average position of the particles remaining the same.

When the pans are heated, the particles in each pan vibrate faster and transfer this energy rapidly to neighboring particles.

The pan with a thicker base has more particles in it than the pan with lighter weight base. Note that, The rate of heat transfer is inversely proportional to the thickness of the material in question. Hence, the thicker the base, the more the number of particles present and the longer the time it takes for the food to cook.

Answer:

Zinc mercury transition metal

Silicon boron metalloid

Oxygen nitrogen non metal

Sodium alkali metal

Explanation:

the correct combo is C

We know sunlight is key factor in photosynthesis so A and D are out.

we also know plants get their bulk by breaking up co2 and using the carbon which releases oxygen as a byproduct so B is also out of the question.

Explanation:

"pure water does not conduct electricity. But some tap water probably can."

The reason why pure water does not conduct electricity is due to the absence of mineral and metal containing salts. Pure water is made up of only Hydrogen and oxygen atom as represented by the formula; H2O

Tap water on the other hand are most likely able to conduct electricity due to the presence of these ions. They may arise from impurities or during treatment processes.

The correct options are;

b . Pure water is H2O

c . Some tap water has minerals, such as iron in it.

Answer:

Metal

Explanation:

Answer:

a. Gases ideales: relación entre todas las variables que influyen sobre los gases

Explanation:

La ecuación del gas ideal da la relación entre las variables; presión, volumen, temperatura y número de moles.

Según la ecuación del gas ideal; PV = nRT

P = presión del gas

V = volumen del gas

n = Número de moles del gas

R = constante de gas

T = temperatura del gas

El número de moles de SO2 se obtiene de;

n = PV / RT

n = 0,5 * 25 / 0,082 * 373

n = 12,5 / 30,586

n = 0,41 moles

Answer:

4th one

Explanation:

a physical change is something u can see, so if the substance changes its properties then thats a physical change.

Explanation:

protons and neutrons.....

...

Answer:

The subatomic particles are Protons and Neutrons.

Answer:

One is the classic example of friction. When two surfaces rub together, they generate thermal energy, or heat. This is a transformation of the mechanical kinetic energy of the objects into the thermal non-mechanical energy (which is small-scale kinetic energy).

Mechanical energy can be used to overcome friction or lost in form of heat in machine parts. Friction and heat are two non-mechanical energy.

Based on the principle of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another.

The two ways mechanical energy can be transformed include the following;

Mechanical energy can be used to overcome friction or lost in form of heat in machine parts, in this process, the mechanical energy (kinetic energy) would be converted into other forms of energy such as heat.

Learn more about conservation of energy here: https://brainly.com/question/166559

Answer:

Humans are modifying the world in many ways, and not all of them for the better. The changes we cause are often severe challenges to animals, plants and microbes in nature, from the introduction of pathogens or exotic invasive species to adding toxic substance or excessive nutrients, or causing climatic change. Often several changes occur at once. Nelson Hairston's lab focuses on freshwater environments, especially lakes and ponds, where some of the species present respond to environmental change with decreases in their numbers, even to the point of extinction, while others may benefit to excess, becoming so dominant that they present problems, as in the case of harmful algal blooms stimulated by nutrient enrichment or climate warming. Hairston's lab studies how individual species, food webs, and whole ecosystems are altered when the environment changes.

One way that some freshwater organisms respond to environmental change is to evolve rapidly. A marked change in the environment favors some characteristics of plants, animals and microbes over others. These character differences are often genetically based so that favored characteristics may increase in the next generation. The shorter the generation time, the faster this evolutionary change can occur. For example, tiny but abundant plankton, eaten by fish and other larger animals, can become adapted to the changed environment within a few years because their generation time is only a few days. Hairston's lab has shown that planktonic "water fleas" (Daphnia), major consumers of suspended algae in lakes, evolved to be tolerant of harmful algae within a decade of the appearance of blooms. This rapid evolution (termed "evolutionary rescue" in conservation biology) raises many intriguing questions, for all environments, not just freshwater: To what extent can we rely on species adapting rather than going extinct when their environment changes? How does the evolution of a species that plays a critical ecological role alter the interactions it has with other species, and the functioning of the entire ecosystem?

Answer:4.5 ×10^22)

Explanation:

no. of particles =no. of mole×avogadro's number of particles no. of particles =0.75×6.02×10^23 no. of particles =4.5 ×10^22

Which solution is the least concentrated?

O 2

Answer:

1144 g of FeS

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

Fe + S —> FeS

From the balanced equation above,

1 mole of Fe reacted to produce 1 mole of FeS.

Therefore, 13 moles of Fe will also react to produce 13 moles of FeS.

Finally, we shall determine mass of 13 moles of FeS. This can be obtained as follow:

Mole of FeS = 13 moles

Molar mass of FeS = 56 + 32

= 88 g/mol

Mass of FeS =?

Mass = mole × molar mass

Mass of FeS = 13 × 88

Mass of FeS = 1144 g

Therefore, 1144 g of FeS were obtained from the reaction.

Answer: The given statement is False.

Explanation:

Alpha particle is a helium nuclei.

Alpha particles are produced when a larger nuclei decays into smaller nuclei in radioactive decay. Alpha particles have mass number and atomic number as 4 and 2 respectively.

General representation of alpha decay :

[tex]^A_Z\textrm{X}\rightarrow ^{A-4}_{Z-2}\textrm{Y}+^4_2\textrm{He}[/tex]

Thus the given statement that alpha particle is composed of [tex]He^{2+}[/tex] ions is False.

The statement of [tex]\rm He^2^+[/tex] ions has formed the alpha particles is true.

Alpha particles are particles that have been similar to the He-4, with the presence of two protons and two neutrons. The alpha particles have the absence of electrons and have been formed during the alpha decay.

[tex]\rm He^2^+[/tex] has been the ion of He with the positive charge indicating the loss of 2 electrons. Thus, in [tex]\rm He^2^+[/tex], there has been 2 protons, 2 neutrons, and 0 electrons.

The atomic configuration of [tex]\rm He^2^+[/tex]has been similar to the alpha particles. Thus, the statement stating, "the alpha particles to be composed of [tex]\rm He^2^+[/tex]ions " is True.

For more information about the alpha particles, refer to the link:

https://brainly.com/question/1685421  

Answer:

B. 2, 3 and 6

Explanation:

The primary materials for a chemic combustion reaction are  Fuel + O2 → CO2 + H2O!

Hope this could help!  （*＾ワ＾*）

Answer:the answer is B

Explanation:

Answer:

It's the epicenter of an earthquake!

p.s. basically that means it's the center

Answer:

the epicentre of an earthquake is the location directly above the hypocenter the surface of the earth (p.s the hypocenter is the location where an earth quake starts )

Answer:

In the social sciences, a social group is two or more humans who interact with one another, share similar characteristics, and have a collective sense of unity. This is a very broad definition, as it includes groups of all sizes, from dyads to whole societies.

Explanation:

Answer:

The meaning of social group is two or more people who interact with one another, share similar characteristics, and collectively have a sense of unity.

Explanation:

Hope this helped

Answer: The concentration of the solution is 0.18 M

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

[tex]Molarity=\frac{n}{V_s}[/tex]

where,

n = moles of solute

[tex]V_s[/tex] = volume of solution in L

moles of [tex]CaCl_2[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{220g}{111g/mol}=1.98mol[/tex]

Now put all the given values in the formula of molality, we get

[tex]Molarity=\frac{1.98mol}{11L}=0.18M[/tex]

Therefore, the concentration of the solution is 0.18 M

Answer:

CH4 + O2 = CO2 + H2O.

Answer:

CH4 + O2 = CO2 + H2O.

Explanation:

Answer:

As KBr

is producing lesser moles of product so, KBr

is limiting reactant and produced potassium chloride=

187.74g

Answer:

Q1 is A.

Q2 is right

Q3 is D.....I dont

really know about this one

Q4 is right

Answer:

see above

Explanation:

check for cfe's

Answer:

temperature

catalyst

surface area