Answer:
Option (A)
Explanation:
Radioactivity is defined as a process in which an unstable atomic nucleus decays continuously and after a specific period of time changes into a much more stable element. During this time of decay, the nucleus emits charged particles (energy) which are known as the α, β and γ particles. These are often emitted in the form of electromagnetic energy and are very dangerous to health.
The radioactive elements decay at a certain rate which is commonly known as the half-life. Half-life is basically defined as the time required by a radioactive substance to decay half of its initial composition.
Thus, the correct answer is option (A).
Answer:
Both are highly reactive.
Explanation:
A has 1 valence electron D has 3
A is sodium D is aluminum
Answer:
20ppm
Explanation:
parts per million are defined as the mass of solute in mg (In this case, mass of DDT) per kg of sample.
To solve this question we must find the mass of DDT in mg and the mass of sample in kg:
<em>Mass DDT:</em>
0.10g * (1000mg / 1g) = 100mg
<em>Mass sample:</em>
5000g * (1kg / 1000g) = 5kg
Parts per Million:
100mg / 5kg =
<h3>20ppm</h3>
Answer: 462 g
Explanation:molar mass is M= 63.55 +2·(12.01+14.01)= 115.59 g/mol.
Mass m= n·M = 4.0 mol·115.59 g/mol= 462.36 g
B is the answer
please mark me brainlist ^^