Answer:
b :)
Explanation:
an exothermic reaction is when heat/light is produced. heart is produced from this reaction so it is exothermic
Answer : The complete chemical equation is,

Explanation :
As we know that, in a chemical equation the reacting species present on left side and the product formed present on right side and a right arrow inserted between the reactants and product that show a chemical reaction taking place.
In the chemical reaction, the phases of the substances are also included and subscripts and superscripts are also used for the numbers.
For the given chemical reaction, the balanced chemical equation including the phases, is given by:

Answer : Both solutions contain
molecules.
Explanation : The number of molecules of 0.5 M of sucrose is equal to the number of molecules in 0.5 M of glucose. Both solutions contain
molecules.
Avogadro's Number is
=
which represents particles per mole and particles may be typically molecules, atoms, ions, electrons, etc.
Here, only molarity values are given; where molarity is a measurement of concentration in terms of moles of the solute per liter of solvent.
Since each substance has the same concentration, 0.5 M, each will have the same number of molecules present per liter of solution.
Addition of molar mass for individual substance is not needed. As if both are considered in 1 Liter they would have same moles which is 0.5.
We can calculate the number of molecules for each;
Number of molecules =
;
∴ Number of molecules =
which will be = 
Thus, these solutions compare to each other in that they have not only the same concentration, but they will have the same number of solvated sugar molecules. But the mass of glucose dissolved will be less than the mass of sucrose.
A Lewis structure is a visual representation of the bonds between atoms and it shows the lone pairs of electrons in molecules. This structure is also referred as Lewis dot diagram. Resonance structure are multiple Lewis structure that describe a single molecule.<span>
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1. Answer;
Copper (ii) carbonate.
The name of the compound CuCO3 is copper (ii) carbonate.
Explanation;
Cu is the chemical symbol for the copper and CO3 is the chemical symbol for the carbonate group and each one of them has valency of two. Therefore, a compound CuCO3 is formed.
2. Answer;
Yes
Ca2+ reacted with Na2S to form CaS and Na+
Explanation:
Calcium ions reacts with sodium sulfide to form calcium sulfide and sodium ions.
For example; a salt of calcium, calcium carbonate reacts with sodium sulfide to form sodium carbonate and calcium sulfide.
3. Answer;
NaCl and Ag+ do not form a product
Explanation;
The reaction between sodium chloride and silver metal will not take place. This is because silver (Ag) is less reactive than sodium metal and therefore cannot displace sodium from its salt. In other words, silver metal is lower in the reactivity series as compared to sodium metal which indicates sodium metal is more reactive than silver.
4. Answer;
Formation of a white precipitate ; this indicates that silver sulfide is insoluble in water.
Explanation;
When an aqueous solution containing Ag+ ions is added to aqueous solution of sodium sulfide (Na2S), there will be formation of white precipitate. Formation of white precipitate indicates that a reaction has taken place to form a water insoluble compound. The water insoluble compound occurs as a precipitate. The white precipitate is silver sulfide (Ag2S)
2 Ag+ (aq) + Na2S(aq) ----- Ag2S (s) + 2 Na+ (aq)