If you start with 40.0 grams of the element at noon, 10.0 grams
radioactive element will be left at 2 p.m. The correct answer between
all the choices given is the second choice or letter B. I am hoping that this
answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.
The model of the atom has dramatically changed over many many years.We learned atoms make up different substances and are the smallest particles of matter, which have subatomic particles that are very small portions of matter. At first scientist only thought there were electrons which are negatively charged.
Answer:
Density by giving the object it's weight/volume. State of matter by giving its chemical substances and physical shape.
Explanation:
State of matter, (solid, liquid, or a gas) determines the main physical property of a substance. If it's a liquid, it would have an indefinite shape/physical appearance. If the object is a solid than the shape would have a definite shape/physical appearance. Density is defined as mass per volume which means the weight of an object divided by the volume determines the density of the object. You would have the volume (the amount of space an object takes up) and the mass (weight of the object) if you have the objects density.
To conclude, both density and the objects state of matter determine the physical properties of a substance. "Density the weight and volume, and the state of matter is the shape/chemical properties of the substance."
Hope this helps.
After 3 half life periods you would have 5 grams of krypton left because half of 40 is 20 half of 20 is 10 and half of 10 is 5
C. 50%
Unless the question is saying he only gets heads once, in which case it would be 0%. Or the coin could have 2 heads. Then it would be 100%.
But I'm pretty sure it's 50%.
