来自MSN3 个月
118 Elements and Their Symbols and Atomic Numbers: Definition, Symbol with Atomic Number
Symbol: A one or two-letter abbreviation used ... the first 20 elements of the periodic table: H - Hydrogen He - Helium Li - Lithium Be - Beryllium ...
Seeking Alpha1 年
PLSR:CA Pulsar Helium Inc.
Pulsar Helium Inc. engages in the identification, acquisition, exploration, and development of helium exploration projects in the United States of America and Greenland. Its flagship project is ...