Which best describes an element?

Correct Answer: 6CO2 + 6H2O -----> C6H12O6 + 6O2

Explanation:

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities.

 

Photosynthesis can be represented using a chemical equation.

 

The overall balanced equation is

 

               $$\begin{gathered} 6 CO 2 + 6 H 2 O ? Sunlight C 6 H 12 O 6 + 6 O 2 \\ S o u r c e o f C a r b o n & O x y g e n + \\ S o u r c e o f E l e c t r o n s & H y d r o g e n + \\ E n e r g y t h a t d r i v e s P h o t o s y n t h e s i s - - - - > \\ S u g a r + G a s p r o d u c e d b y s p l i t t i n g w a t e r . \end{gathered}$$

 

Where 

CO2 = carbon dioxide 

H2O = water

C6H12O6 = glucose 

O2 = oxygen.

Correct Answer: Nitrogen

Correct Answer: Acetic acid

Explanation:

In the form of vinegar, acetic acid is known from very early times. It is got by oxidation of fermented liquors (10-15%, alcohol) by air under the influence of a bacteria called 'mycoderma acetic'

Correct Answer: A solution is a homogeneous type of mixture of two or more substances A solution has two parts:: 1 A solute and 2 A solvent The solute is the substance that dissolves, and the solvent is the majority of the solution

Correct Answer: 4

Explanation:

The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.

Correct Answer: We know that polar substances are soluble in polar solvents and non polar substances are soluble in non-polar solvents only Here the hydrocarbons are non-polar molecular substances and water is a polar solvent So water can't dissolve hydrocabons Hence, as hydrocarbons are non-polar substances, they are insoluble in water as it is a highly polar solvent

Correct Answer: copper(II) hydroxide

Explanation:

Sodium chloride:

The solubility rules tell you that all halides are soluble with the exception of those formed with siver, mercury, and lead ions. Since this is not the case here, sodium chloride will be soluble.

 

Silver nitrate:

It is soluble because all nitrates are soluble, without exception.

 

Potassium sulfate:

It is soluble because all sulfates are soluble with the exception of those formed with silver, calcium, barium, mercury, lead, and strontium ions.

 

Copper (II) hydroxyde:

It is insoluble because all hydroxides are insoluble with the exception of those formed with alkali metal ions and barium.

Correct Answer: An ion

Explanation:

An electrically charged atom or group of atoms formed by the loss or gain of one or more electrons is called an Ion.

Cation:

An ion is a cation (positive ion) if it is created by electron loss and is attracted to the cathode in electrolysis.

Anion:

An ion is an anion (negative ion) if it is created by an electron gain and is attracted to the anode.

 

The valence of an ion is equal to the number of electrons lost or gained and is indicated by a plus sign for cations and a minus sign for anions.

Ex: Na +, Cl?, Ca ++,...

Correct Answer: Ethylene

Explanation:

Allotropes are different structural modifications of an element, that is, each of two or more different physical forms in which an element can exist.

 

Carbon is capable of forming many allotropes due to its valency. Well-known forms of carbon include charcoal, diamond, graphite, buckminsterfullerene and graphene.

 

Hence, Ethylene is not an allotrope of Carbon.

Correct Answer: 3' > 2' > 1'> NH3

Explanation:

The order of basicity in ammonia is different in gaseous phases vs. aqueous phases due to hydrogen bonding.

 

So in gaseous phases it's the well known: 3' > 2' > 1'> NH3. Just so we're on the same page, this is due to the inductive effect of electron donating alkyl groups--they destabilize the lone pair on nitrogen atom, making nitrogen more basic.

 

But in aqueous phase, the order is slightly different: 2'> 1'> 3' > NH3.