Question

write down 3 examples of elements each having valency I and 2.​

Answer 1

Answer:

Explanation:The history of science covers the development of science from ancient times to the present. It encompass all three major branches of science: natural, social, and formal.[1]

The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3000 to 1200 BCE.[2][3] Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes.[2][3] After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Latin-speaking Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages,[4] but continued to thrive in the Greek-speaking Eastern Roman (or Byzantine) Empire. Aided by translations of Greek texts, the Hellenistic worldview was preserved and absorbed into the Arabic-speaking Muslim world during the Islamic Golden Age.[5] The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived the learning of natural philosophy in the West.[4][6]

Answer 2

Explanation:

sodium NA+1

AMMONIA NH4+1

IRON FE+2

MARK ME AS BRAINLIST