A double replacement reaction occurs when the ionic parts of two ionic compounds are exchanged.
Reaction 1 results in a product which is a single compound. No ionic parts are exchanged.
Reaction 3 results in one compound being separated into its elemental parts. No ionic parts are exchanged.
Reaction 4 has two reactants, but Pb is an element and not an ionic compound. No ionic parts are exchanged.
Hence, the answer is Reaction 2. Both NaBr and Ca(OH)2 are ionic compounds. Br - is the anion in NaBr, and (OH)2 is also an anion. Ionic parts are exchanged.
Answer: The height of the mountain is 1,331.4 meters (approximately)
Step-by-step explanation: From the information given, the students were standing at point b which is 800 meters from the base of the mountain and the angle of elevation from that point is 59°. Assuming that the ground is level, we can derive a right angled triangle from this set of details and hence we have triangle ABC, where angle β is the reference angle, (59 degrees), BC is the distance from the students to the base of the mountain (800 meters) and the line AC is the height of the mountain.
The line AC is the opposite, since angle B is the reference angle, therefore we shall use the trigonometric ratio as follows;
Tan β = opposite/adjacent
Tan 59 = AC/800
Tan 59 x 800 = AC
1.6643 x 800 = AC
1331.44 = AC
AC ≈ 1331.4
Therefore the height of the mountain is approximately 1,331.4 meters
Answer:
25.3 lb
Step-by-step explanation:
We can multiply the whole by the percentage to find the part. Since 15.9% is equal to 0.159, the weight of fat is 159*0.159 = 25.281. Round this to the nearest tenth, and we get 25.3 pounds.
We can create the equation like this:
(x +2) * (x +0)
x^2 + 2x + 0 = 0
Uh it can really be anything. You should try and be more specific: see if you did the whole problem.
