Help pls it’s so hard

Answer:

Explanation:

First Question:

Melting is a physical process that involves the phase transition of a substance from its solid to its liquid state. Burning, on the other hand, is a chemical process that involves a substance being broken down and changed into different substances. It's still the same substance, though: water.

Second Question:

Mass is therefore never conserved because a little of it turns into energy (or a little energy turns into mass) in every reaction. But mass+energy is always conserved. Energy cannot be created out of anything.

Answer:

one Sodium (Na) atom, two oxygen (O) atoms, two carbon (C) atoms, and three hydrogens (H) atoms

Explanation:

this question is in reference to the formation and naming of ionic compounds. Specifically, they want you to give examples of three ionic compounds with a metal to nonmetal ratio of 2 to 1. That means we need to have two metal atoms to metal ions, which are typically cat ions for every one non metal atom or an ion. In order for this to occur, we need to have the metal with half the charge of the nonmetal or the non metal with double the charge of the metal. So an example might be something like sodium sulfide. Sodium has one valence electron. It can give up sulfur needs to valence electrons in order to achieve an octet. So we need to. Sodium seems to give up one electron each to total so that sulfide can achieve an octet. Another one might be potassium oxide. Similar scenario. We've got potassium giving up one valence electron oxygen requiring too. So we need to potassium to supply the to valence electrons that oxygen needs to achieve an octet and lithium. Also in Group one A and alkali metal wants to give up just one valence electron to achieve an octet well to achieve, I guess a duet to be more like helium, and so it gives up one. If we have two of them, then we can provide the to valence electrons that sulfur needs. So this is sodium sulfide, potassium oxide and lithium sulfide. Remember when we name Ionic compounds? We named the Cat Ion with the name of the element and the anti on with the name of the Element, but with the ending oven of ID, a suffix of ID because each one of the cat ions donated their valence electrons to the anti on so the an ion could achieve an octet. Then all of the's will have an octet of valence electrons. Sulfur had six sodium had one. There were two of them, so we have a total of eight.

The metals that can form only one type of ion are Li, Al, Ca, Ba, Rb, W,Na, Mg and  Sr. They are called alkali metals.

Cobalt, Co is stable in both +2 and +3 oxidation state. So it can variable.

Lithium, Li only have +1 charge. So it is invariable from one compound to other.

Lead, Pb is variable as it has +2, +4 charge in which it is stable.

Pd has +2, +4 charge in which it is stable. So, It is variable.

Copper, Cu has +1, +2 charge. It is also variable. Potassium, K has only +1 charge. It is invariable. Aluminum, Al has only +3 charge. It is invariable.

Cesium, Cs is only stable in +1 charge. It is invariable. Molybdenum, Mo is stable in +4 and +6. It is variable. Calcium, Ca and Barium Ba are stable in +2 charge. It is invariable.

Rubidium, Rb is stable in +1 charge. It is invariable. Tungsten, W is stable in +6 charge. It is invariable. Iron, Fe is stable in +2, +3 charge. It is variable. Sodium, Na is stable in +1 charge. It is invariable. Mg and Sr are stable in +2 charge. It is invariable. Vanadium, V has +2, +3, +4, +5 charges. So, It is variable.

To know more about alkali metals

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Answer:

You have to write the full question

Answer:

C

Explanation:

The azimuthal quantum number can take values from 0 to (n-1)

So in answer C n= 3, l can take values between 0

and 2.

l can't be 3.

ml can take values from -l to +l.

Hope you understood

Answer:

the molar mass of Mg(NO3)2

the mass of the water added the density of the Mg(NO3)2

the volume of water used

Calculate the number of moles of Mg(NO3)2 used to make up this solution. 42.0 g of Mg(NO3)2 is equivalent to___ mol Mg(NO3)2.

Now calculate the molarity of the solution, giving your answer to the correct number of significant digits.

Molarity of Mg(NO3)2 = ___M

Answer:

can u tell the question in english

Answer:

Explanation:

b

A is the petal and b is the leaf. I think.

Answer:

30.8 percent quartz, 4.5 percent feldspar, 3.6 percent carbonate, <0.5 percent iron oxides, 60.9 percent clay minerals, 1 percent organic material, and 2 percent other materials.

The volume of titrant required for the titration would be 27.44 mL

From the illustration, the initial titrant volume was 2.51 mL. This figure represents the initial reading on the burette.

In the same vein, the final volume of the titrant was 29.95 mL. This figure represents the final reading on the burette.

In order to get the volume of titrant used:

Volume of titrant used = final volume - initial volume

                             = 29.95 - 2.51

                                = 27.44 mL

More on the volume of titrant used in titrations can be found here: https://brainly.com/question/4250180

Answer:

c2H5

Explanation:

H. H

|. |

C-C- H

|. |

H. H

Answer:

nonreactive

Explanation:

Answer:

1 would be the answer

protons = atomic # I think

Answer:

hydrogen

Explanation:

hydrogen has the atomic number of 1 which means that hydrogen has one proton and is neutral so it has one electron as well.

A chemist analyzes two samples. One sample contains 14 g of element X and 6.0 g of element

The complete oxidation of the monosaccharide shown will create a carboxylic acid.

Monosaccharides can be oxidized to carboxylic acids. Recall that monosaccharides have an aldehyde or ketone group at one end and a CH2OH group at the other end.

For the monosaccharide shown, oxidation may lead to the conversion of COH group  to acid (-COOH). This confirms the presence of -COH yielding the product C4H8O5.

Learn more: https://brainly.com/question/2192784

Explanation:

E = hf

c= f × lamda

f= c/ lamda

c= speed of light

f= frequency

lamda = wavelength

E = h c/ lamda

E = 6.626 × 10^-34 Js × 3 × 10^8 ms-1 / 589 × 10^-9 m

= 3.37 × 10^15 J

Answer:

10

Explanation:

Basically same as last question but the number is before the compound :)

Answer:

1

Explanation:

Answer:

Um.....

Explanation:

Thanks for the pts

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Answer: Lipids are one of the important nutrients needed by the body to supply energy and essential fatty acids required by the organism. Solid alcohols are a class of steroids, which are steroids containing hydroxyl groups. Lipids is a general term for oils, fats and lipids. 2, the characteristics are different: fat consists of c, h, o three elements. Fats are triacylglycerides made up of glycerol and fatty acids.

Answer:

D

Explanation:

the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of an object

Answer:

option C 5

hope this answer helps you dear! take care

Answer:

5, the coefficient is the number right before the variable. The ² and ³ (even though Mines on top and yours is on the bottom) are not coefficient because. . . well it just doesn't make sense.

Answer:

cotton

Explanation:

which is typically spun into fine yarn for mechanical weaving or knitting into cloth.

Answer:

The bowling ball has kinetic energy as it moves toward the pins.

Explanation:

Answer:

Most of it is transferred to the pins, but some of it is changed into heat and sound energy.

Explanation:

study island

Answer:

Transition Metal

Explanation:

If you look at a periodic table, you can see that Cu is a transition metal.

Answer:

translation to English please