When atoms, the basic units of chemical elements, combine into chemical compounds, they form molecules. Organisms have many different kinds of molecules, from water and simple salts to complex molecules such as carbohydrates, fats, proteins, and deoxyribonucleic acid (DNA). One protein, called hemoglobin, carries oxygen in the blood and is what makes blood red. Hemoglobin contains atoms of six different elements—carbon, hydrogen, oxygen, nitrogen, sulfur, and iron.
Answer: see attach file
Explanation: In order to solve this problem we have used the Gaussian law in the different regions. Details are included in the attach.
when you carry the 2 and add the 3 its Z
Answer: Use less water
only turn on lights when needed
electrical cars
less gas usage
Explanation:
Answer:
15.8m/s
Explanation:
This problem can be solved by taking into account the conservation of the momentum. In this case the momentum of the astronaut and the bag of tools must equal the momentum of the astronaut and the bag of tool after the astronaut throws the bag.
Hence, we have

where ma and va are the mass and velocity of the astronaut, mb and vb are the mass and velocity of the bag, after the astronaut throw the bag. The velocity v is the velocity where the astronaut has the bag of tool
By taking into account that the velocity of the astronaut must be zero to keep him near of the space station, we have that vb = 0.
Thus
