Explanation

• A Neutralization reaction is a specific type of reaction where an acid and a base react to form a salt and water only, with no other products.
• This reaction is characterized by the elimination of acidic and basic properties, resulting in a neutral solution.
• Example: HCl (acid) + NaOH (base) → NaCl (salt) + H2O (water)

Explanation

 Copper was first used by man over 10,000 years ago

The period following the use of copper is sometimes referred to as the Copper Age or Chalcolithic Age. 

Explanation

 Silicon is the second most abundant element in the Earth's crust,

Making up a large portion of most rocks and minerals, particularly silicates, which are composed of silicon and oxygen. 

Earth's Crust Elements

1 Oxygen (O) 46.1%

2 Silicon (Si) 28.2%

3 Aluminum (Al) 8.2%

4 Iron (Fe) 5.6%

Explanation

Species is the basic unit of classification.

Species are a group of organisms that are morphologically similar and can interbreed.

1. Kingdom
2. Phylum
3. Class
4. Order
5. Family
6. Genus 
7. Species

Explanation

Direct current is produced when electrons flow constantly in one direction.

It's abbreviated as "DC".

Since direct current flows in one direction only, its electrical pressure or voltage is always oriented in one direction, or "polarity".