where was hydrogen discovered

Answer:

manganese, Mn

Explanation:

From the question, we have;

The number of electrons in the 3d sub level = 5

The kind of element = d-block element

On the periodic table, the elements with electrons in the 3d-sublevel in increasing order are;

Sc, 3d¹ 4s²

Ti  3d² 4s²

V  3d³ 4s²

Cr 3d⁵ 4s¹

Mn 3d⁵ 4s²

Fe 3d⁶ 4s²

Co 3d⁷ 4s²

Ni 3d⁸ 4s²

Cu 3d¹⁰ 4s¹

Zn 3d¹⁰ 4s²

The elements with 5 electrons in their 3d-sublevel are chromium Cr and manganese, Mn however the electronic configuration of chromium is given as 3d⁵ 4s¹ rather than 3d⁴ 4s² due to the minor difference in the gap of energy between the 3d and the 4s orbital as such the element that has the main characteristic of 5 electrons in its 3d sub level is manganese, Mn.

Answer: C

Explanation:

There are 761.4 grams of CS2 in 10.00 mol.

To calculate the amount of grams present in a given amount of moles, the molar mass of the substance must be used, as follows:

                                        [tex]m = MM \times mol[/tex]

In this way, just perform the following operation:

                                          [tex]m = 76.14 \times 10[/tex]

                                         [tex]m = 761.4 grams[/tex]

Thus, there are 761.4 grams of CS2 in 10 mol of the substance.

Learn more about mole calculation in: brainly.com/question/15693285

Each isotope of Oxygen has a different number of neutrons

The elements in nature have several types of isotopes

Atomic mass is the average atomic mass of all its isotopes

Isotopes are atoms has the same number of protons but has a different number of neutrons.

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

Some of the isotopes of oxygen are:

[tex]\tt _8^{16}O,_8^{17}O,_8^{18}O[/tex]

Each isotope has 8 protons and 8 electrons but has a different number of neutrons

For O-16: number of neutrons = 16-8 = 8

For O-17: number of neutrons = 17-8 = 9

For O-18: number of neutrons = 18-8 = 10

Answer: Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above

Explanation:

Answer:

25

Explanation:

Answer:

0.7L

Explanation:

Given parameters:

Initial volume V₁  = 0.4L

Initial temperature T₁  = 20°C  = 20 + 273  = 293K

Final temperature  = 250°C  = 250 + 273  = 523K

Unknown:

Final volume V₂ = ?

Solution:

To solve this problem, we apply Charles's law.

It states that "the volume of a fixed mass of a gas varies directly as the absolute temperature if the pressure is constant".

 mathematically;

        [tex]\frac{V_{1} }{T_{1} } = \frac{V_{2} }{T_{2} }[/tex]  

V and T are temperature values

1 and 2 are initial and final states;

  Insert the parameters and solve;

   [tex]\frac{0.4}{293}[/tex]   = [tex]\frac{V_{2} }{523}[/tex]  

        V₂   = [tex]\frac{523 x 0.4}{293}[/tex]   = 0.7L

Answer:

In order to identify a chemical property,we look for a chemical change.Chemical changes involve chemical reactions and are often observed through a change in colour or odor

abiotic are non living things and biotic are living beings

and complete cells with well developed nucleus

these are the organism which make their own food by photosynthesis

these are the organism which depend on other organism for food

Monera

Protista

fungi

plantae

animalia

Answer:  

1.A POWER DRILL COULD SET YOUR HOUSE ON FIRE, IN THEORY.

2.STICKY NOTES COME OFF EASILY BECAUSE THEIR ADHESIVE IS UNEVEN. ...

3.GUM IS CHEWY BECAUSE IT'S MADE OF RUBBER. ...

4.OFFICE BUILDINGS ARE EVER-SO-SLIGHTLY TALLER AT NIGHT. ...

5.A LEGO BRICK CAN SUPPORT 770 POUNDS OF FORCE. ...

6.POLISHING SHOES IS LIKE FILLING IN A ROAD'S POTHOLES.

Explanation:

Answer:

X = 2-propanol

Y = 2-chloropropane

Z = propene

Explanation:

Secondary alcohol is an alcohol in which the carbon that the functional group (OH group) is attached to is also attached to two alkyl group. Examples are 2-propanol and 2-butanol.

The secondary alcohol referred to in the question here is 2-propanol and it reacts with PCl₅ as seen below

H₃C-CH-CH₃ + PCl₅ ⇒ H₃C-CH-CH₃ + HCl + POCl₃

        |                                     |

       OH                                Cl

The alkylhalide produced there is 2-chloropropane. Thus, we can see that X is 2-propanol and  Y is 2-chloropropane.

When this 2-chloropropane undergoes dehydrohalogenation (removal of hydrogen and halogen) an alkene is formed. The reaction is seen below

H₃C-CH-CH₃   (-HCl)    ⇒  H₃C-CH=CH₂

        |

       Cl

The alkene produced (as seen above) is propene.

Confirmation: When propene undergoes ozonolysis, the compounds produced are ethanal and methanal as seen in the equation below

                                                   O

                                                 /    \

H₃C-CH=CH₂ + O₃  ⇒  H₃C - CH  CH₂    [-O]  ⇒ CH + CH₂  

                                                 ||     ||                     ||        ||

                                                O    O                    O      O

The final products as seen above are methanal and ethanal

Answer:

the right answer is:

Explanation:

How to Balance: NaHCO3 + HC2H3O2 = NaC2H3O2 + CO2 + H2O|

Answer:

NaHCO3 +C6H8O7

Explanation:

these are the formulas of sodium hydrogen carbonate and citric acid

Answer:

Yes, it becomes 2 of H20 which is water

Answer:

A:Substance A is a strong acid and substance B is a weak base

Explanation:

From this information, we can conclude that substance A is a strong acid and substance B is a weak base.

A strong acid is one that ionizes completely in solution. Most strong acids are usually concentrated. 100% dissociation is a complete ionization.

A weak base ionizes slightly in an aqueous solution. 25% dissociation is weak ionization.

Answer:

a

Explanation:

The superscript 3 in 4pº tell that there are 3 electrons in this orbital

In an atom there are levels of energy in the shell and sub shell

This energy level is expressed in the form of electron configurations.  

There are 4 sub-shells in the shell of an atom, namely s, p, d, and f. The maximum number of electrons for each sub-shell is  

• s: 2 electrons  

• p: 6 electrons  

• d: 10 electrons and  

• f: 14 electrons  

Charging electrons in the sub-shell uses the following sequence:  

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.  

Arsenic is an element with the symbol As, which has an atomic number of 33 and a mass number of 75

Electron configuration of As : [Ar] 3d¹⁰4s²4p³

Each superscript shows the number of electrons that occupy each orbital

For the p orbital there are a maximum of 6 electrons, while the 4p³ orbital shows that there are 3 electrons in this orbital

Answer:

It chemistry babe

Explanation:

Answer:

Figure  7.4.1 : Balancing Equations. You cannot change subscripts in a chemical formula to balance a chemical equation; you can change only the coefficients. Changing subscripts changes the ratios of atoms in the molecule and the resulting chemical properties. For example, water (H2O) and hydrogen peroxide (H2O2) are chemically distinct substances. H2O2 decomposes to H2O and O2 gas when it comes in contact with the metal platinum, whereas no such reaction occurs between water and platinum. The subscripts are part of the formulas and once the formulas for the reactants and products are determined, the subscripts may not be changed. The coefficients indicate the number of each substance involved in the reaction and may be changed in order to balance the equation. The equation above indicates that one mole of solid copper is reacting with two moles of aqueous silver nitrate to produce one mole of aqueous copper (II) nitrate and two atoms of solid silver.

Explanation:

Answer: 6

Explanation:

Element                Quantity

Copper                        1

Silver                           2

Nitrogen                      1

Oxygen                        6

Answer:

d is the correct answer i think

Answer:

As the police car moves towards them, the pitch of the police car's siren goes up because the sound waves get closer together in front of the police car. When the police car moves away from the person, the pitch goes down because the waves spread out behind the police and that makes the frequency go down.

Explanation:

Answer:

River ecosystems are flowing waters that drain the landscape, and include the biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts.

Explanation: it should be both

Answer:

Ecosystems mostly consist of both - abiotic and biotic factors. For that reason the answer which would properly address your question would be A - biotic and abiotic factors. Biotic factors are considered to represent the part of nature that are living and affect other organisms while abiotic factors are things which do not affect other living compounds.

The theoretical yield of iron metal : 16.418 g

A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.

Reaction

2 Fe₂O₃ + 3 C ⇒ 4 Fe + 3 CO₂

mol Fe₂O₃ (MW=159,69 g/mol) :

[tex]\tt \dfrac{23.5}{159.69}=0.147[/tex]

mol  Fe₂O₃ : mol Fe = 2 : 4

mol Fe :

[tex]\tt \dfrac{4}{2}\times 0.147=0.294[/tex]

mass Fe(the theoretical yield) :

[tex]\tt 0.294\times 55.845~g/mol=16.418~g[/tex]

Answer:

The correct answer with signfigs is 16.4 for the first part

The second box is 88.4

Explanation:

Answer:

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

f is the force

m is the mass

From the question we have

[tex]a = \frac{47}{7} \\ = 6.714285...[/tex]

We have the final answer as

Hope this helps you

Answer: This historical data could have helped with the development of Tokyo’s new flood protection system:

historical frequency of flooding

amount of flooding during each storm

computer models forecasting the worst possible flooding

Explanation:

The frequency of flooding can help Tokyo measure when the next flood will be.

The amount of flooding can help Tokyo determine how much water will come during the flood.

And computer models forecasting the worst possible flood can help reach out to people and tell whether they need to evacuate or what  they should plan for.    

Answer:

Reacting of 5 cm3 of baking soda with 100 cm3 of vinegar should produce 0.083 moles of CO2 gas, 0.083 moles of sodium acetate, and leave 0.01 moles of sodium bicarbonate unreacted.

Explanation:

Explanation:

Glass is not a liquid in the strictest sense of the word. But it is also not a standard solid. The chemistry of glass is complex and research is ongoing, but the current consensus is that glass is a phase of matter all its own, known as an "amorphous solid". Scientists refer to any amorphous solid as a "glass". Glass transitions are highly complex and cannot be treated in the same way as traditional phase transitions.

Answer:

It's a liquid state before its cooled.

Sodium Carbonate commonly known as Sodium Carbonate is a inorganic compound which used in detergents and to soften the water. Its chemical formula is [tex]Na_{2}CO_{3_[/tex]. It is carbonate base

Lemon juice contain citric acid whose chemical formula is [tex]C_{6} H_{8} O_{7}[/tex]. Citric acid is a weak organic acid thus It is used for disinfectants and cleaning as well.

When Lemon Juice and Washing Soda react, the reaction is just an acid-base reaction and forms trisodium citrate and carbonic acid. The latter is then dissociated into Carbon Dioxide and Water. Carbon Dioxide escapes in the form of bubbles and Sodium Citrate(salt) and Water behind.

(citric acid)+ (sodium carbonate)= (trisodium citrate)+(water)+(carbon dioxide)

            [tex]2C_{6}H_{8}O_{7} + 3Na_{2}CO_{3} ---> 2Na_{3}(C_{6} H_{3} O_{7})_{2} + 3H_{2}O + 3 CO_{2}[/tex]

Answer:

centrifugation

Explanation: