Evidence of the existence of prehistoric humans in the Himalayan region has been found in various archaeological sites, particularly in the Shivalik Hills, Kashmir Valley, Himachal Pradesh, Uttarakhand, and Nepal. Some key findings include:

1. Paleolithic (Old Stone Age) Evidence

• Sohan Valley (Siwalik Hills, Punjab-Haryana region): Stone tools and hand axes from the Lower Paleolithic period suggest early human habitation.
• Kashmir Valley: Fossilized remains and stone tools from Pahalgam and Burzahom indicate prehistoric human activity.

2. Mesolithic (Middle Stone Age) Evidence

• Burzahom (Kashmir Valley): Neolithic tools and pit dwellings suggest a transition from hunter-gatherer societies to settled life.
• Leh-Ladakh region: Rock carvings (petroglyphs) show early human artistic expression and hunting scenes.

3. Neolithic (New Stone Age) Evidence

• Burzahom: Pit dwellings, tools, pottery, and evidence of domestication of animals.
• Guler (Himachal Pradesh): Stone tools and artifacts indicating Neolithic settlements.

4. Copper and Early Iron Age Evidence

• Malari (Uttarakhand): Rock paintings and artifacts from early civilizations.
• Dhauli Ganga Valley (Uttarakhand): Petroglyphs showing early human activity.

These findings indicate that prehistoric humans lived in the Himalayan region, adapting to its harsh climate and developing tools, dwellings, and early forms of art and agriculture.

The periodic table was discovered by Dmitri Mendeleev, a Russian chemist, in 1869. He arranged the known elements based on their atomic mass and observed that elements with similar properties appeared at regular intervals, which led to the creation of the periodic law. Mendeleev’s table predicted the existence and properties of elements that had not yet been discovered at the time. His work laid the foundation for the modern periodic table, which is now organized by atomic number rather than atomic mass.