Universe is almost 70% made up of __________?
Correct answer: B. Hydrogen
- A. Helium
- B. Hydrogen
- C. Chlorine
- D. Carbon
Explanation
Hydrogen makes up approximately 70% of the universe by mass because it was formed abundantly in the early universe and is the main element in stars. The likely wrong choice is helium, which is also abundant but contributes roughly 25% by mass, not about 70%.
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About Periodic Properties and Trends
Periodic properties arise from electron configuration and effective nuclear charge, producing trends in atomic and ionic radius, ionization energy, electron affinity, electronegativity, metallic character and reactivity. Comparisons run across periods and down groups, with attention to common exceptions. The topic also relates these trends to the behavior of s-block and p-block elements.
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1,359 free s-Block and p-Block Elements MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
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