Answer:
4.375 milligram
Explanation:
Applying,
A = A'(2ᵃ/ⁿ)............. Equation 1
Where A = original amount of actinium-228, A' = amount of actinium-228 left after decay, a = Total time, n = half life
make A' the subject of the equation
A' = A/(2ᵃ/ⁿ)........... Equation 2
From the question,
Given: A = 70 milligram, a = 24.52 hours, n = 6.13 hours
Substitute these values into equation 2
A' = 70/(2²⁴°⁵²/⁶°¹³)
A' = 70/(2⁴)
A' = 70/16
A' = 4.375 milligram
Answer:
Oxygen and Magnesium together, OMg?!?!
Umm what kind of question is that but i think gain lol
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
Thus, we perform the operations in order to obtain:
So we solve for x as shown below:
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!
1.the chemical change color from colorless to purple
2. A yellow gas forms
3.a brown solid forms in the bottom of the beaker
4.the temperature of the chemicals rises 15 Celsius
Explanation:
All of the options are proofs that chemical change has occurred.
A chemical change is one with the following properties:
- A new kind of matter is usually formed as seen by the gas evolution and the formation of the insoluble precipitate i.e brown solid at the bottom of the beaker.
- They are not easily reversible.
- Usually accompanied by energy changes as seen in the rise in temperature.
- Color changes can also infer chemical changes in a reaction.
learn more:
Chemical change brainly.com/question/9388643
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