Cosmology is the study of the grand scale of the universe. You need astronomical observation because then there would be no proof to cosmological theory.
I believe the answer is salt. because it is a compound of two distinct elements that can be broken down without changing the properties of substance.
A pure substance is a substance that are made up of only one type of an atom or one type of a molecule. Pure substances may be further broken down into elements and compounds.
Answer:
An open system
Explanation:
An open system is a system in which both matter and energy are exchanged freely between the system and the surroundings.
An example is a pot of water boiling on the stove. The surroundings (the stove) can supply heat energy to the water and the water can escape into the atmosphere.
A <em>closed system</em> is a system in which energy but not matter is exchanged freely between the system and the surroundings.
An example is a pressure cooker on the stove. The surroundings (the stove) can supply heat energy to the food inside, but no matter can escape through the closed lid.
An <em>isolated system</em> is a system in which neither energy nor matter can be exchanged between the system and the surroundings.
An example is a thermos of hot soup. The cap prevents matter from escaping and the shiny interior reflects heat back into the soup.
Answer:
2 grams
Explanation:
One MOLE of hydrogen atoms contains the same number of atoms as the number of hydrogen molecules in one MOLE of hydrogen molecules, i.e., Avagadros number. However, one mole of hydrogen atoms has a mass of 1 gram while one MOLE of hydrogen molecules has a mass of 2 grams.
I would go with B. Not everyone can learn this skill.
