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Chapter 2
Overall Questions on Chapter 2
Question | Answer |
---|---|
What is chemistry? | The science that considers the composition of matter and how this composition changes. |
What is matter? | It is anything that has weight and takes up space such as solids, liquids and gases. |
What is matter composed of? | Elements |
How many elements are known? naturally? | 111 and 92 |
How many elements does the human required? | 20 |
What are 95% of elements in the human? | oxygen, carbon, hydrogen, and nitrogen |
How do elements vary? | In size, weight, and the way they interact with each other. |
What does the nucleus of an atom contain? | Protons & neutrons. Electrons move around them. |
Electrons & neutrons or protons are equal? | Protons. This makes it is neutral. |
How do you get the Atomic number? | The number of protons |
How do you get the Atomic Weight? | Number of protons and neutrons. Electrons have very light weight. |
What 3 particles do atoms have? | electrons, protons, neutrons |
What is the simplest form of an atom? | Hydrogen |
1 atom + 1 atom= | molecule |
Electons & Protons have the same amount. Neutrons..... | Vary in amount |
What are ions? | Atoms that gain or lose elctrons and become electrically charged. |
What are catalysts? | Particular atoms or molecules that can change the rate of a reaction without being consumed in the process. |
What is kinetic energy? | When energy is actually doing work (moving objects such as a bouncing ball) |
What is potential energy? | Inactive or stored energy. (batteries of an unused toy) |
What are compounds? | Atoms of different elements such as water which contain definite kinds and numbers of atoms. |
How many molecules does a grain of salt have? | 1.23 x 10 to the 23rd |
What is a compound | Made of different elements |
What is an electrolyte? | When some compounds release ions when they dissolve in water |
What does PH do? | measures hydrogen ion concentration in the blood. |
What is Acid? | Electrolytes that release hydrogen ion H+ in water. |
What is a base? | Electrolytes that release ions that combine with hydrogen ions. |
What chemicals do Organics have? | carbon and hydrogen |
What are nonelctrolytes? | Organics that dissolve in water but do not produce ions. |
What are electrolytes? | Chemicals that rest, dissolve in water and release ions. |
Name 3 Inorganic substances | Water, oxygen, salts or carbon dioxide |
What is oxygen used for in the body? | release energy from glucose and drives metabolic activities. |
What does carbon dioxide do? | Waste product that is exhaled from the lungs |
Name 3 things salts do | Transports substances into or out of cells, muscle contractions, nerve impulses |
Where are salts abundant? | tissues and fluids |
Name 4 organic substances | Carbohydrates, lipds, proteins, nucleic acids |