The half-life of cobalt-60 is 5.26 years. After 10.52 years, 5 grams of a 20-gram sample will remain is TRUE
<u>Explanation:</u>
Mass of cobalt = 20 g
Half-life = 5.26 years
Mass remains after 10.52 years = 5 g
This can be solved by using given below formula, 
= initial mass
t = number of years from when the mass was m_0
m(t) = remaining mass after t years
Number of half-lives = 
Number of half-lives = 
Number of half-lives = 2
At time zero = 20 g
At first half-life = 
= 10 g
At second half life = 
= 5 g
The given statement is true.
Answer:
Organic chemistry
Explanation:
Organic material like alcohols and esters are composed mostly of carbon structures, hence the branch is referred to as organic chemistry
Answer:
a pencil being sharpened
freezing water
boiling water
Explanation:
a physical change doesn't change the chemical structure of an object. That is why the other 2 are wrong
Answer:
1400000 cm
Explanation:
14 km equals to 1400000 cm (14 km = 1400000 cm)
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Answer:
May I assume "ethanol acid is just ethanol (it has one slightly acidic H atom). If so, the molar mass is 46.02 g/mole.
Explanation:
We have 30 cm^3 [30 ml] of 1.0 M (1 mole/liter) [1 dm³ = 1 liter].
That is 1 mole/liter. 30 ml would contain (0.030 liter)*(1 mole/1 liter) = 0.03 moles.
