Answer:
A
Explanation:
Photosynthesis is reverse combustion, thus, water and carbon dioxide should be reactants. Photosynthesis also needs sunlight, so A it is.
<u>Answer:</u>
<u>Ion</u>
Ion is a charged particle.
A neutral atom contains equal number of positive protons and negative electrons
When an electron is lost or gained the atom becomes a charged particle which is called as an ION.
For example
Na is an atom which contains 11 electrons and 11 protons(= to atomic number)
When Na loses an electron it will have 11 positive proton and 10 negative electron and Thus, Na will become 
, a charge particle which we call it as sodium ion.
Cl is an atom which contains 17 electrons and 17 protons(= to atomic number)
When Cl loses an electron it will have 17 positive proton and 18 negative electron and Thus, Cl will become 
, a charge particle which we call it as chloride ion.
When an ion is positively charged it is called as a cation
When an ion is negatively charged it is called as an anion.
Salt is formed when an acid reacts with a base.
The cation of the base combines with the anion of the acid to form the salt.
HCl is acid and NaOH is a base forms salt NaCl and water.
is an anion of the acid and is the cation of the base combines to form NaCl salt .
and 
combines to form 
Answer:
5.87 ×10¹⁹ molecules.
Explanation:
From the question given above, the following data were obtained:
Mass of C₆H₅NO₂ = 12 mg
Number of molecules of C₆H₅NO₂ =?
Next, we shall convert 12 mg to g. This can be obtained as follow:
1 mg = 10¯³ g
Therefore,
12 mg = 12 mg × 10¯³ g / 1 mg
12 mg = 0.012 g
Next, we shall determine the mass of 1 mole of C₆H₅NO₂. This can be obtained as follow:
1 mole of C₆H₅NO₂ = (12×6) + (5×1) + 14 + (16×2)
= 72 + 5 + 14 + 32
= 123 g
Finally, we shall determine the number of molecules present in 12 mg (i.e 0.012 g) of C₆H₅NO₂. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of C₆H₅NO₂ = 6.02×10²³ molecules
123 g of C₆H₅NO₂ = 6.02×10²³ molecules
Therefore,
0.012 g of C₆H₅NO₂ = 0.012 × 6.02×10²³ / 123
0.012 g of C₆H₅NO₂ = 5.87 ×10¹⁹ molecules.
Thus, 12 mg (i.e 0.012 g) of C₆H₅NO₂ contains 5.87 ×10¹⁹ molecules.
By dissolving salt in seawater the seawater acts as the solvent. The definition of a solvent is: liquids that dissolve other substances.
