Answer: 
Explanation: A double displacement reaction is one in which exchange of ions take place.
The compounds which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
Thus the exchange of ions take place and all the compounds are soluble so the chemical formulas are followed by the symbol (aq).
To get the ∆S of the reaction, we simply have to add the ∆S of the reactants and the ∆S of the products. Then, we get the difference between the ∆S of the products and the ∆S of the products. If the <span>∆S is negative, then the reaction spontaneous. If the otherwise, the reaction is not spontaneous.</span>
Answer:
The atomic number of<span>N<span>157</span></span>
The number of protons is 7
The number of electrons is 7
The number of neutrons is 8
Explanation:
The atomic number of Nitrogen is 7 because Nitrogen has 7 protons.
The seven protons attract 7 electrons in the ground state.
If the atom had fewer or more than 7 protons the atom would not be Nitrogen.
The mass of the atom is the sum of protons and neutron. so
p + n = mass ( protons (p) and neutrons(n) both have an atomic mass of one
7 + n = 15 subtract 7 from both sides
<span>7−7+n=15−7</span>
n = 8
Compounds are made up of elements that exist in a fixed proportion. These elements are composed of atoms. Now, the atom has subatomic particles (proton, neutron and electrons), however, these particles lack the ability to take part in chemical reactions by themselves; the smallest unit of a compound that can take part in a chemical reaction, therefore, is an ATOM.
Thus, an AT<span>OM is the smallest unit of a compound that retains the unique properties of the compound</span>
Answer:

Explanation:
A mole is any quantity of a substance that contains 6.02 × 10²³ particles. At standard temperature and pressure, or STP, 1 mole of as is equal to 22.4 liters. This is true for any gas, regardless of the specific kind.
Although it is not specified, we can assume this gas is at STP. Let's set up a ratio using this information: 22.4 L/mol

Multiply by the given number of liters: 12

Flip the ratio so the liters of chlorine cancel.




The original measurement of liters has 2 significant figures, so our answer must have the same.
For the number we found, that is the hundredth place.
The 5 in the thousandth place tells us to round the 3 up to a 4.

12 liters of chlorine gas at STP is approximately <u>0.54 moles of chlorine gas.</u>