Answer:
9000 BC
Explanation:
Although various copper tools and decorative items dating back as early as 9000 BCE have been discovered, archaeological evidence suggests that it was the early Mesopotamians who, around 5000 to 6000 years ago, were the first to fully harness the ability to extract and work with copper.
They both have two electron shells
<h3>Further explanation</h3>
The period 2 element lies in the second row of the periodic system.
Consists of the elements: lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neon
atomic number : 3
electron configuration : [He] 2s¹
atomic number = number of proton=number of electron(in neutral atom)
So Li have 3 protons and 3 electrons
Because it fills the 2s orbital it has 2 shells
atomic number : 8
electron configuration : [He] 2s²2p⁴
So O have 8 protons and 8 electrons
Because it fills the 2s and 2p orbital it has 2 shells
So Lithium (Li) and Oxygen (O) are both have two electron shells
I think <span>3H2+N2==>2NH3</span>
Answer:
The temperature is 298.5 K, which corresponds to 0.50°C.
A jacket would be appropriate clothing for this weather.
Explanation: Hope this helps:)
Explanation:
The more reactive element replaces less reactive element during chemical reaction.
Since, potassium is more reactive than beryllium. When potassium reacts with beryllium choride, it replaces beryllium and forms potassium chloride and produces beryllium.
