Which of these statements describes a chemical property?

Answer:

x = 3 and y= 2

Explanation:

Given equations:

           8x - 3y  = 18  - ---- (I)

           5x + 6y = 27 -------(II)

Solve this problem by elimination;

  In the elimination method, we simply find a common term that can make one of the variables in the two equation the same. Then we either add or subtract to remove the variable.

 Mulitply equation (i) by 5 to give equation III

 Mulitply equation (II) by 8 to give equation IV

     5(8x - 3y) = 5(18) ------- III

     8(5x + 6y) = 8(27) ------- IV

   40x - 15y = 90------- III

   40x + 48y = 216  ------- IV

Subtract  equation III and IV;

        -15y - 48y = 90 - 216

         - 63y = -126

                y = 2

Solve for x;

      40x - 15y = 90;

       40x - 15(2) = 90

         40x - 30 = 90

           40x = 90 + 30

              40x = 120

                 x = 3

Answer:

"Revolution" refers the object's orbital motion around another object.

plz mark brainliest :DD

Answer:

Explanation:

A 5.430 g mixture of FeO and Fe3O4 is reacted with excess of oxygen to form 5.779 g Fe2O3. Find the masses of FeO and Fe3O4 present in the mixture.

I found the answer by doing the following:

Fe2O3 = 159.69 g/mol

FeO = 71.745 g/mol

Fe3O4 = 231.535 g/mol

5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3

x + y :rarrow: 0.03619 mol Fe2O3, where x = FeO and y = Fe3O4.

This implies that y = 0.03619 - x.

5.430 g = x*71.745 g/mol + (0.03619 - x)*231.535g/mol

x = 0.01846 mol * 71.745 g/mol = 1.324 g FeO

y = 0.03619 - 0.01846 = 0.01773 mol * 231.535 g/mol = 4.105 g Fe3O4

My question is why doesn't the following work:

4FeO + O2 :rarrow: 2Fe2O3

4Fe3O4 + O2  :rarrow: 6Fe2O3

_______________________

2FeO + 2Fe3O4 + O2 :rarrow: 4Fe2O3

5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3

Product:reactants in question are in a 2:1 ratio as given by the stoichiometric coefficients.

0.03619 mol / 2 = 0.01810 mol of FeO and 0.01810 mol Fe3O4.

0.01810 mol FeO * 71.745 g/mol = 1.299 g FeO

0.01810 mol Fe3O4 * 231.535 g/mol = 4.191 g Fe3O4

Obviously this doesn't work because the original mixture is 5.430 g and not 1.299 g + 4.191 g = 5.490 g. Why doesn't this work the way I think it should? Thank you.

Answer: To calculate the atomic mass add up the mass of protons and neutrons.

I hope I helped!

Two or more than two atoms with different physical or chemical properties can not combine together to form an element. An element  cannot be broken down into simpler substances by a chemical change. The correct option is option A.

Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.

Element is the basic unit of any compound and molecule which can not be broken further. Mixture, solution and compound are composed of two or more than two elements which can be further broken down easily.

Therefore, an element  cannot be broken down into simpler substances by a chemical change. The correct option is option A.

To know more about element, here:

https://brainly.com/question/8460633

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Answer:

The periodic table is organized in non-metals metals and metalloids, in in terms of trends and patterns you may want to talk about the the density of the elements or the mass of per unit of measurement of whatever you're going to use sorry that could be much help but I hope it helps.

Answer: 255 pm

Explanation: Hope this helps!

Answer:

26.1g

Explanation:

Cclf3

=35.5

F=54/101.5

Mass=mol*mm

=0.25*1015

=26.1g

Answer:

Rubidium= [Kr] 5s^1

Calcium= [Ar] 4s^2

Aluminium= [Ne] 3s^2 3p^1

Explanation:

A noble gas configuration begins with the elemental symbol of the last noble gas prior to the atom. The symbol is then followed by the remaining electrons.

Hope this helped! good luck :)

Answer:

The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.

Explanation:

Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. However, with time the number of pioneer species decreases.

The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.

Answer:

4.00 g/mL

Explanation:

Density is mass divided by volume (g/mL).

Mass of rock = 21.58

Volume of rock = 25.4 - 20.0 = 5.4mL

Density of rock = 21.58g / 5.4mL = 3.99629 g/mL

Round to the lowest number of significant figures which is three = 4.00 g/mL

Answer:

The empty cup

Explanation:

Got it right on the test

Answer:

A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus and minus signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than are chemical names and structural formulae.

Explanation:

Have A Wonderful Day !!

The relative atomic mass of element A : 6.075 u

The elements in nature have several types of isotopes

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.

So Isotopes are elements that have the same Atomic Number (Proton)

Atomic mass is the average atomic mass of all its isotopes

Mass atom X = mass isotope 1 . % + mass isotope 2.% ...

Element A

mass number of isotope 1 = 6 , percent : 92.5%

mass number of isotope 2 = 7, percent : 7.5

Relative atomic mass of element A

[tex]\tt = 92.5\%\times 6+7.5\%\times 7\\\\=5.55+0.525=6.075~u[/tex]

Answer:

false

Explanation:

Hope the answer was usefull for us

Answer:

false. there is the surface soil, which has a lot of partly decayed stuff, topsoil, which has minerals and organic material, subsoil, which is made from sand, silt, and clay that hasn't been broken down, and parent material, which is the place where not much living things live in, except for gigantic tree roots. then there is the bedrock, which is; you guessed it:rock entirely.

Explanation:

Answer:

The tetanus vaccine is a dose of the bacterium Clostridium Tetani, in inactive form or even a surface molecule that helps the body to actively form the antibody.

The tetanus vaccine has coverage for life, it is mandatory in those countries where the disease became common, such as the USA, Argentina, Chile, Uruguay among others.

Before a surgical act or a suspicion of exposure with this bacterium, the booster of the tetanus vaccine should be administered quickly.

Explanation:

Tetanus disease generates a tetanization of all the muscles of the organism, generating spasmodic contractions, which make it impossible to function and develop life when it affects the diaphragm as it makes breathing impossible.

Tetanization does not affect differently in age or sex, it only consists of contamination with the bacteria to be sufficient.

The sources of contagion are areas of mud or earth, rusty cutting or sharp elements, and poorly hygienic or abandoned areas. In order for the bacteria to be transmitted or the transmission route to be fulfilled, there must be a lesion of loss of continuity of the epithelium or mucosa.

Answer:

the answer is B!!!

Explanation:

It is incorrect because it should have a total of eight electrons with two electrons between each H and O

Lewis structure shows the form of bonds that occur in the valence electrons of an element or compound

This bonding usually occurs in covalent bonds

Valence electrons are electrons used in a chemical bond

The main group elements usually have valence electron configurations in the ns and np subshells, While the transition elements in the subshells (n-1) d and ns.

Element O has 6 valence electrons

Element H has 1 valence electron

To achieve stability, the element O needs 2 more electrons which are obtained from 2 electrons from the H element, while the H element needs 1 electron to be stable

So that a covalent bond is formed

Answer:

D

Explanation:

( I hope that this helps )

Answer:

The answer is d

Explanation:

Answer:

They are in the same family, with similar characteristics.

Explanation:

The elements in a given group of the periodic table are in the same family and with similar characteristics.

Answer: The water vapor transfers thermal energy to the air.

Explanation:

Answer:

Explanation:

Convert mass in gms .. 987 gms

Density = mass/ volume

= 987/4.52 x102

= 2.18 g/mL

Answer:

Tea is getting hot on the stove.  

2) As the tea and water gets hot, some combined molecules of tea and water will escape from the teapot.  

3) Those escaped molecules now have the entire free space of the entire room to float around in, which they do (because they have high kinetic energy due to being heated).  

4) Hence, in this scenario, your nose will detect a few of those molecules and you smell hot or warm tea.  

5) Cold tea would be a different story. Cold beverages like cold tea do not have the kinetic energy where molecules can 'break free' of the surrounding container. Someone could be sitting in the room having a can or bottle of cold tea and you would not notice that when you walked in the door.

Answer

Explanation:

an atom is usually define as a perfect balance of electrons and protons

Answer:

Smallest to Largest:

Clay is smaller then 1/125 mm

Silt is 1/256- 1/16 mm

Sand is 1/16-2 mm

Pebble is 2-64 mm

Cobble is 64-256 mm

Boulder is greater then 256 mm

Explanation:

Answer:

Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion

Explanation:

pleaseee mark brainliest <3!

In the calorimeter, the heat received is the same as the heat released  

Q abs = Q release

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

Q released by a metallic ore and absorbed by water at calorimeter

Q ore = Q water

m = 0.5 kg = 500 g

c = 4.18 J/g–°C.

Δt = 24.3 - 22 = 2.3

[tex]\tt Q=m.c.\Delta t\\\\Q=500\times 4.18\times 2.3=4807~J[/tex]

Q ore = Q water = 4807 J

m ore = 3.5 kg = 3500 g

Δt = 100 - 24.3 = 75.7

[tex]\tt 4807=3500\times c\times 75.7\\\\c=0.018~J/g^oC[/tex]