All isotopes of elements with atomic 82 or lower are not radioactive.
Correct Answer:
Verified
Q45: An atom of K-40 contains 40 neutrons.
Q46: An atom of Pb-208 contains 126 neutrons.
Q47: Isotopes always have the same atomic number.
Q48: Isotopes always have the same mass number.
Q49: All elements with atomic number 83 or
Q51: A positron is a positively charged electron.
Q52: In beta decay the atomic number and
Q53: In alpha decay both the mass number
Q54: In positron decay the atomic number decreases
Q55: After four half-lives the activity of a
Unlock this Answer For Free Now!
View this answer and more for free by performing one of the following actions
Scan the QR code to install the App and get 2 free unlocks
Unlock quizzes for free by uploading documents