Answer:- 
Explanations:- It's a double replacement reaction where a precipitate of silver(I)bromide is formed. A dpuble replacement reaction in general looks as AB + CD \rightarrow AD + CB
To balance the equation we need to multiply gold compounds on both sides by 2 and the balanced equation is..

Sodium/Atomic number
11
Gold/Atomic number
79
Potassium/Atomic number
19
Silicon/Atomic number
14
Ultraviolet as ultraviolet light waves are around 420 nm like stated in the photo
Answer:
.........................................................
Explanation:
Answer:
0.053moles
Explanation:
Hello,
To calculate the number of moles of gas remaining in his after he exhale, we'll have to use Avogadro's law which states that the volume of a given mass of gas is directly proportional to its number of moles provided that temperature and pressure are kept constant. Mathematically,
V = kN, k = V / N
V1 / N1 = V2 / N2= V3 / N3 = Vx / Nx
V1 = 1.7L
N1 = 0.070mol
V2 = 1.3L
N2 = ?
From the above equation,
V1 / N1 = V2 / N2
Make N2 the subject of formula
N2 = (N1 × V2) / V1
N2 = (0.07 × 1.3) / 1.7
N2 = 0.053mol
The number of moles of gas in his lungs when he exhale is 0.053 moles