Answer:
Atom is a the smallest particle of a chemical element that can exist.
Molecules is a a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
Particles is a minute portion of matter.
A particle can be a single atom or a molecule ( a group of atoms held together by chemical bonds).
Answer:
The isotope with the greatest number of protons is:
- <u>option D: Pu-239, with 94 protons</u>
Explanation:
The number of <em>protons</em> is the atomic number and is a unique number for each type of element.
You can tell the number of protons searching the element in a periodic table and reading its atomic number.
Thus, this is how you tell the number of protons or each isotope
Sample Chemical symbol Element atomic number # of protons
A Pa-238 Pa protactinium 91 91
B U-240 U uranium 92 92
C Np-238 Np neptunium 93 93
D Pu-239 Pu plutonium 94 94
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
False. Carbon is definitely one of the 92 naturally occurring elements within the periodic table.
