Pleseee help me pretty please ✨

Answer:

4th one

Explanation:

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

Answer:

Cows and other ruminant animals (like goats and sheep) emit methane, a potent greenhouse gas, as they digest grasses and plants. This process is called “enteric fermentation,” and it's the origin of cows' burps.

Explanation:

Answer:

Q1 is A.

Q2 is right

Q3 is D.....I dont

really know about this one

Q4 is right

Answer:

The other name for this isotope is a proton. This is because it contains just a  single proton.

Explanation:

H+

Protons = 1

Electrons = 1 - 1 = 0 (The + sign means it has lost a single electron)

Neutrons = 0

Answer:

Gas

Explanation:

I dunno but a lucky guess i guess

Answer:

anode: magnesium

cathode: nickel

Explanation:

edg. 2021

Answer:

Temperature is a measure of the average kinetic energy of the particles in an object. When temperature increases, the motion of these particles also increases. (That should give you the answer if you read closely first sentence)

Answer:

2 FeCl2 + Cl2 -> 2 FeCl3

According to numbers in reaction

Amount of Cl2 is half of FeCl2

Explanation:

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:

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 answer is 12M

Explanation: 3.0mol/ 0.25L =12M

12M is the molarity of a solution made from dissolving 3.0 moles of Saline (NaCl) in 0.25 L of solution.

The amount of molecules of molecules divided by the quantity of liters in solution is the definition of molarity, a concentration unit in chemistry. It is crucial to comprehend how it is calculated as well as when to employ it in comparison to other units because it is among the most widely used concentration units.

A chemical solution's concentration is measured in molarity (M). It refers to the solute's moles per liter of solution. To be clear, this is not the same as the liters of solvents (a common mistake).

molarity = number of moles of solute/ volume of solution in litre

molarity =3.0mol/ 0.25L

             =12M

Therefore, 12M is the molarity of a solution made from dissolving 3.0 moles of Saline (NaCl) in 0.25 L of solution.

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Answer:

Explanation:  A conversion factor is a number used to change one set of units to another, by multiplying or dividing. When a conversion is necessary, the appropriate conversion factor to an equal value must be used. For example, to convert inches to feet, the appropriate conversion value is 12 inches equal 1 foot.

Answer:

i don't know

Explanation:

Answer:

There are six liquid elements present in the periodic table. They are bromine,mercury ,caesium,gallium,rubidium and francium.

The metalloids; boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At) are the elements found along the step like line between metals and non-metals of the periodic table.

The gaseous element group; hydrogen (H), nitogen (N), oxygen (O), fluorine (F), chlorine (Cl) and noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) are gases at standard temperature and pressure (STP).

Explanation:

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:

In the middle of the forest.

Explanation:

They have to bury the remains in the middle of the forest at the Forensic Osteological Research Center in order to study the decomposition of the dead person. By studying the decomposition of dead person we can get a lot of information which can be used in the study of criminal cases and solving of crimes. The middle place in the forest is a perfect place to bury the remains due to presence of huge amount of microbes as well as insect that helps in the decomposition.

Answer: 0.16 g H2

Explanation:

Mg+ H2SO4= MgSO4 + H2

Atomic massof Mg is 24

Molecular mass of H2 is 2

So,

24g Mg produce 2 g H2

1g Mg produce (2÷24)= 0.083 g H2

2.00g Mg produce (0.083×2) g H2

   = 0.16 g H2

 0.16g of hydrogen is formed when 2.00g of magnesium.

The mass of hydrogen gas formed when 2.00g of magnesium is equal to 0.165 g.

The chemical equation of a reaction is said to be a balanced equation when the number of atoms of substances is equal on either side of the equation.

Evergy balanced chemical equation must follow the law of conservation of mass according to which the total mass of the substances present on the reactant side should be equal to the total mass of substances present on the product side.

Given, the balanced chemical equation of the reaction of Mg and sulfuric acid:

[tex]Mg + H_2SO_4 \longrightarrow MgSO_4 +H_2[/tex]

One mole of magnesium produces hydrogen gas = 1mol

Given the mass of magnesium = 2g

The number of moles of Mg = 2/24.3 = 0.082 mol

Then the number of moles of hydrogen gas formed = 0.082 mol

The mass of the hydrogen gas = 0.082 × 2 = 0.165 g

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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:

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:

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Explanation:

protons and neutrons.....

...

Answer:

The subatomic particles are Protons and Neutrons.

Answer: Hello, This is my most favorite class so I know this is right.

The most Reactive metal source is Copper.

Explanation:

This is the most reactive because it contains Lithium supplement.

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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

Hello Mistyann!

First you need to know amount of barium phosphate is

Half of potassium phosphate, also 2.18 mol.

Molar mass of Barium phosphate is 3·137.2 + 2·(30.97+4·16) g/mol

You can calculate it yourself dear.

Now mass is amount of substance · molar mass.

It has been an honour to teach you, dear,

God bless!

Answer:

Zinc mercury transition metal

Silicon boron metalloid

Oxygen nitrogen non metal

Sodium alkali metal

Explanation:

Answer:

c the number of electrons

Answer:

Ture

Explanation:

Ture

True

True

True

Answer:

V=f*(wavelength)

V= (800)(20m)

16000m/s

Explanation: