Froming a hypothesis is the first step of the scientific methhod true or false

1 meter = 1000 km

2500 meter = 2500/1000 km

= 2.5 km

Answer:

it should be letter c

Explanation:

I hope this help

Answer:

The formula of water is H20

Answer:

[tex]\boxed {\boxed {\sf B. \ 0.5 \ M}}[/tex]

Explanation:

Molarity is a measure of concentration in moles per liter. The formula for calculating molarity is:

[tex]molarity= \frac{moles \ of \ solute}{ liters \ of \ solution}[/tex]

There are 2 moles of a compound or the solute. There are 4 liters of water or the solution.

Substitute the values into the formula.

[tex]molarity = \frac{ 2 \ mol}{ 4 \ L}[/tex]

Divide.

[tex]molarity= 0.5 \ mol /L[/tex]

1 mole per liter is equal to 1 Molar, so the solution's molarity of 0.5 mol/L is equal to 0.5 M.

[tex]molarity = 0.5 \ M[/tex]

The molarity of the solution is 0.5 Molar and choice B is correct.

Answer:

Below!

Explanation:

Isotopes are elements with a similar chemical makeup and the same atomic number, but a different atomic mass and number of neutrons . An example of this would be carbon-12, carbon-13, and carbon-14. Three isotopes of the element carbon that have the same 6 protons but have a different neutron count. A simple way to explain isotopes would be to say that they are just different "versions" of an element.

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The empirical formula is the simplest formula of a chemical compound.

To find the empirical formula, we take the following steps;

1) O - 88.10/16,      H - 11.190/1

  O - 5.5,               H - 11.19

  O - 5.5/5.5,        H - 11.19/5.5

  O -  1,                 H - 2

Empirical formula = OH2

2) C - 41.368/12  H - 8.101/1,   N - 32.162/14,   O - 18.369/16

   C - 3,               H - 8,           N - 2,                  O - 1

   C - 3/1,            H - 8/1          N - 2/1                 O - 1/1

    C - 3,             H - 8,           N - 2,                   O - 1

Empirical formula = C3H8N2O

To obtain the molecular formula where n = number of atoms of each element;

Molecular weight = 174.204 g/mol

[ 3(12) + 8(1) + 2(14) + 16]n = 174

n= 174/88

n = 2 (to the nearest whole number)

Hence, we have;

[C3H8N2O]2

The molecular formula is C6H16N4O2

3)  C - 19.999/12,  H - 6.713/1,   N - 46.646/14,   O - 26.641/16

    C - 2,                H - 7,            N -  3,                 O - 2

    C - 2/2,            H - 7/2,         N -   3/2,             O - 2/2

    C - 1,                H - 4,            N -  2,                  O - 1

Empirical formula - CH4N2O

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Answer:

if wrong sorry ok????

Explanation:

freezing point depression is a phenomenon that describes why adding a solute or solvent results in the lowering of the freezing point of the solvent

Answer:

A and D are the answers

Explanation:

the other two don't make sense

The statements C and D are correct, i.e., curly hair have different protein structure from straight hair and curly hair results from a change in the gene.

Proteins are biomolecules made of amino acids. Proteins are very essential to all living things and contributes the body structure. Proteins are mainly up taken through diet and they are the main source of energy.

Hair is made of keratin protein. Keratin makes up our skin and nails too.Curly hair is originating by birth not developing over time. Curly hair is more likely to be occurring through inheritance.

The protein structure the hair follicle is some more bend for curly hair. Curly hair and straight hair originates from different gene traits. The gene type is inherited from the parents.

Hence, for people with curly hair have different protein structure and it result from a change in gene that code for hair structure. Thus options C and D are correct.

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Explanation : số mol glucose 3.8M là :

n = Cm . V = 3.8 . 25 =95

=> Cm khi pha loãng = [tex]\frac{n}{V}[/tex] = [tex]\frac{95}{250}[/tex] = 0.38M

According to molar concentration, the  concentration of a solution formed by diluting 25.0 ml of a 3.8 M glucose solution to 250 ml is 0.38 M.

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions given it is calculated as M₁V₁=M₂V₂,on substitution, M₂=3.8×25/250=0.38 M.

Thus,  the  concentration of a solution formed by diluting 25.0 ml of a 3.8 M glucose solution to 250 ml is 0.38 M.

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Explanation:

here's the answer to your question

Answer:

1 Ca(NO3)2

Calcium- Ca, Valency 2

Nitrate- NO3, Valency 1

AFTER CRISS CROSS:

Ca1(NO3)2

Ca(NO3)2

2 sodium bicarbonate = NaHCO3

Na = Sodium = (Na)+

HCO3 = bicarbonate = (HCO3) -

Na HCO3

3 magnesium   nitrite

   +2                 _ 1

Mg2(NO3)2

4 Na    Cl

    +1    _1

formula NaCl

5 hydrogen         sulphide  

H                       SO4

+1                       _2

formula H2SO4

6  H    Cl

  +1     _1

HCl

7 AL2     HSO4

  +2        -2

AL2(HSO4)3

8  NH4   Cl

   +1      _1

NH4Cl

9 NH4     SO4

  +1           _2

(NH3)2SO4

10  H   NO3

    +1    _1

HNO3

The reaction between H2SO4 in a mixture of KI and MnO2 yields iodine which reacts with hypo solution​ by titration and the iodine is decolorized.

Iodine is decolorized.

The first reaction stated in the question occurs as follows;

2 KI (aq) + 2 H2SO4 (aq) + MnO2 (s) → MnSO4 (aq) + K2SO4 (aq) + I2 (s) + 2 H2O (l)

The reaction here is the formation of iodine from MnO2 and KI in the presence of dropwise H2SO4.

Hypo is the common name of sodium thio-sulphate or sodium hypo-sulfite.

The equation of the titration reaction is;

2Na2S2O3 + I2→ Na2S4O6 + 2NaI

When this reaction takes place, iodine is decolorized due to its reduction to I^-.

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Answer: 1.86*10^-7M

Explanation:

Answer:

B. 1.86 x 10^-7 M

Explanation:

Answer:

False

Explanation:

Answer:

This is called a hypothesis, which can be identified by the if... then... format.

So, the correct option is B. Form a hypothesis.

Let me know if this helps!

Answer:

C

Explanation:

Answer:

A linear molecule has a bond angle of 180°

Explanation:

Chemistry Teacher.

Chemical Engineer.

Forensic Scientist.

Geochemist.

Biochemists

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Analytical Chemist

Envionmental chemist

Water Chemist

Catalysis

Answer:

C 760 mm of hg

because this is the atmospheric pressure at sea level

Answer: A reaction element are those elements that can take part in a chemical reaction.

Explanation:

An element is made up of atoms that has the same atomic number. It is the basic material of which all matter is composed of. These elements cannot be broken down further into smaller substances by any chemical reaction. Each element has a unique number of protons in its atom. For example,

--> a hydrogen atom has 1 proton,

--> a Helium atom has 2 protons,

--> a Lithium atom has 3 protons, and

--> a carbon atom has 6 protons.

A chemical reaction on the other hand involves rearrangement of the constituent atoms of reactants to create different substances as products. The bonds between atoms are either broken or created to form new molecules. There are different types of chemical reaction which includes:

--> Decomposition reaction

--> Neutralization reaction

--> single displacement reaction and

--> combustion reaction.

Answer:Water contains Oxygen the purified the methane gas

Explanation:

Answer:

1;1, 2;1, 3;1, 1;2, 1;1, 3;2, 1;3, 2;3, 1;1.

I hope this will help.

Answer:

This is what the answer looks like

Explanation:

The correct lewis structure of methane(CH4)

C. H:C:H:H

Answer:

Potentials of any other electrodes are compared with that of the standard hydrogen electrode at the same temperature. Hydrogen electrode is based on the redox half cell: 2 H+(aq) + 2 e− → H2(g)..

Answer:

B. The carbons on either side of the double bond are Pointed in opposite directions