Why was helium absent from Mendeleev's original periodic table of 1871?
A) Helium is unstable.
B) Helium is radioactive.
C) Helium had not been discovered.
D) Helium occurs only in compounds.
E) none of the above
Correct Answer:
Verified
Q19: What is the term for a chemical
Q20: What is the term for an atom
Q21: Why was argon absent from Mendeleev's original
Q22: Which of the following is an inner
Q23: What is the term for the elements
Q25: Which of the following scientists contributed to
Q26: Which fourth period transition element has the
Q27: Why were noble gases absent from Mendeleev's
Q28: Which of the following is a representative
Q29: Which of the following is a transition
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