Question

QUESTION 2 Humans (Homo sapiens) have existed in their current form for around _______ years, and agriculture began about ____ years ago 1. 50,000; 20,000 2. 200,000; 10,000 3. 100,000; 2,000 4. 500,000; 10,000

QUESTION 3 Water has many unusual and important characteristics that make it a requirement for life to exist as we know it. What best explains the ultimate reasons for these characteristics? That is, what is the underlying reason that explains all the other things about water that we talk about as being required for life?

1. Water is electronegative 2. Water is a polar molecule, and the hydrogen atoms are electronegative 3. the Oxygen atom in water has 8 protons compared to 1 in each in the Hydrogens atoms 4. The Hydrogens in the water molecule are electronegative, conferring polarity to the molecule

Answer 1

1. Humans (Homo sapiens) have existed in their current form for around 2. 200,000 years, and agriculture began about 10,000 years ago

2. 3. the Oxygen atom in water has 8 protons compared to 1 in each in the Hydrogens atoms

The water molecule is composed of 10 protons and 10 electrons. 8 protons and 8 electrons from one oxygen atom and 2 electron and 2 proton  from  the two hydrogen atoms. Since it has the same number of protons and electrons, the water molecule is neutral and makes it unique that make it a requirement for life to exist as we know it