Answer:
When observing how thallium reacts with the air of the earth's atmosphere, its hardness or resistance resembled sodium, it was not investigated further to classify it correctly
Explanation:
Now it is known that they contain different numbers of valence electrons and that thallium is a heavy metal like lead and that they have similar characteristics except for their melting point where thallium is higher.
Atoms according to the kinetic molecular theory, are described in a solid to simply be vibrating in fixed positions, and not moving rapidly in the container. Because of this, they take a fixed volume and have fixed shape.
Explanation:
here's the answer to your question
Vectors include magnitude & direction so the third option is the correct answer :)
12.5% of strontium-90 would remain in a sample after three half-lives have passed. Half-life automatically means 50% of the original amount would remain.
