Answer:
The answer is most likely A. Definite proportions
Explanation:
The Law of Definite proportions states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation.
Whats do you want to know?
A) a column
example: earth alkaline metals
The correct answer is D.
Echo refers to the sound that is heard when a sound wave is reflected back from a surface. An echo sound is made when a sound wave traveled through the air, hit a hard surface and get reflected back. Generally, hard surfaces reflect sound wave while soft surfaces absorb sound waves. Reflected sound waves are used in application of some devices that are used in range and direction finding.
It has 2 valence electrons
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