Answer:
142.82 g
Explanation:
The following data were obtained from the question:
Volume of water = 12 mL
Volume of water + gold = 19.4 mL
Density of gol= 19.3 g/cm³
Mass of gold =.?
Next, we shall determine the volume of the gold. This can be obtained as follow:
Volume of water = 12 mL
Volume of water + gold = 19.4 mL
Volume of gold =.?
Volume of gold = (Volume of water + gold) – (Volume of water)
Volume of gold = 19.4 – 12
Volume of gold = 7.4 mL
Finally, we shall determine the mass of the gold as follow:
Note: 1 mL is equivalent to 1 cm³
Volume of gold = 7.4 mL
Density of gol= 19.3 g/cm³ = 19.3 g/mL
Mass of gold =?
Density = mass /volume
19.3 = mass of gold /7.4
Cross multiply
Mass of gold = 19.3 × 7.4
Mass of gold = 142.82 g
Therefore, the mass of the gold pebble is 142.82 g
thx but it's actually 143
Distance and time is needed for determining speed
Explanation:
A 57.9 g sample of glass is cooled by 2.70'C how much heat does it release
1560
Answer:
<u>2 years</u> to decay to a mass of 50g.
Explanation:
given:
100g of substance with a half life of 2 years
to a mass of 50g
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
ln 2 0.693
Half life T1/2 = ---------- = -----------
λ λ
where λ = rate constant
The initial amount of 100 grams is decaying to a mass of 50 grams is half of its initial value.
Therefore, it will take 2 years for the decay.
