Length of wood = 1.2 m
Carlos wants to cut it into 3 equal parts.
So, length of each part = (1.2/3) m = 0.4 m = (0.4×1000) mm = 400 mm
Answer:
12 mmilligrams of Po-218 was the mass of the original starting material
Explanation:
The half-life of a radioactive material is the time taken for half the amount ofnthe original material present in a radioactive material to decay or disintegrate.
After each half-life, half the original material present at the start remains.
For the radioactive polonium-218 having a half-life of 3.04 minutes, it means that if 1 g is the starting material, after 3.04 minutes, 1/2 g will be remaining; after, 6.08 minutes 1/2 of 1/2 which is 1/4 of the starting material will be remaining; and after 9.12 minutes, 1/2 of 1/4 = 1/8 g will be remaining.
From the question, number of half-lives undergone after 9.12 minutes = 9.12/3.04 = 3 half-lives.
After 3 half-lives, 1/8 of the original material is remaining.
1/8 = 1.50 mg
The original mass of the sample at the start = 1.50 mg × 8 = 12 mg
Therefore, 12 milligrams of Po-218 was the mass of the original starting material.
The melting points of sugar and salt are above 20°C.
<h3>What is melting point?</h3>
The melting points of substances refer to the temperature at which solid substances gain enough energy to become liquids.
The room temperature is approximately 20°C. At this temperature, sugar and salt are solids. This means that the melting temperature of both substances is above 20°C.
More specifically, sugar will melt around 180 °C while salt will melt at a temperature slightly above 800 °C.
More on melting points can be found here: brainly.com/question/25777663
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We may say sodium sulfate is 32.37% sodium, 22.57% sulfur, and 45.06% oxygen; or, 32.37% sodium and 67.63% sulfate. The total is 100% in either case. We now have two sets of numbers which show mass relationships among the elements in sodium sulfate: (1) the formula mass and (2) the percentage composition.
Answer:
True
Explanation:
The percentage yield of a reaction , is given by the formula -
Percentage yield = (actual yield)/(theoretical yield) * 100
Actual yield = the exact amount of yield obtained from an experiment
Theoretical yield = the calculated yield of the experiment.
The denominator value i.e. theoretical yield can never exceed the numerator value , i.e. the actual yield ,
Hence,
percentage yield can never be more than 100% .