The answer is 9.03 × 10²⁴<span> molecules.
</span><span>Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance.
Make the proportion.
</span><span>6.02 × 10²³ molecules per 1 mol
</span>x per 15 mol
6.02 × 10²³ molecules : 1 mol = x : 15 mol
x = 6.02 × 10²³ molecules * 15 mol * 1 mol
x = 90.3 × 10²³ molecules
x = 9.03 × 10 × 10²³ molecules
x = 9.03 × 10²³⁺¹ molecules
x = 9.03 × 10²⁴ molecules
Answer: negative , from , to , exothermic
Explanation:
An endothermic reaction is a type of chemical reaction in which energy is absorbed from the surrounding. The temperature of the surrounding decreases.
An Exothermic reaction is a type of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases.
Endothermic reactions are those in which heat is absorbed by the system from the surroundings and exothermic reactions are those in which heat is released by the system to the surroundings. 
for Endothermic reaction is positive and
As on dissolution of salt, the temperature of water increases, the heat has been released from system into surroundings and thus is negative.
Answer:
then it would still be 101.3
Explanation: because if it's constant that means it remained still
Answer:
46 g of sodium
Explanation:
Sodium reacts vigorously with fluoride gas to form NaF as shown
2Na (s) + F2 (g) ------> 2NaF (s) (Na = 23, F = 19)
2 moles of Na reacts with 1 mole of F2 to produce NaF
By calculating the molar mass of the elements involved in the reaction then multiplied by the mole, the mass can be obtained.
23 * 2 g/mol of Na reacts with 1 * 19 g/mol of F2
46 g/mol of Na reacts with 19 g/mol of F2 to produce NaF
Since the mole ratio is 2 to 1 and 19 g of F2 is used for the reaction, 46 g of sodium will be consumed for the reaction to be achieved.
Answer:
In the arrangement of particles within any atom, the outermost sort of particle is always the electron.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other.
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
