Atoms
What part of an atom is positive?
Proton
What is a substance that is only made of one type of atom?
Element
According to the law of conservation of mass, mass cannot be __________ or destroyed.
Created (or made)
What element has 1 proton in its atoms?
Hydrogen
If I burn paper, is it a chemical or physical change?
What part of an atom is negative?
Electron
What is a substance made up of 2 or more elements bonded together?
I have a piece of paper weighing 3g. If I change it physically, by cutting it, what will the total mass be?
3g
How many protons are in an atom of cobalt (Co)?
27
If I bake a cake, is it a chemical or physical change?
Chemical
What part of an atom is neutral?
Neutron
What is a substance that is made of 2 or more substances that are not all chemically bonded together?
Mixture
If a chemist mixes 20g of hydrogen, and 10g of oxygen, how much will there be after it reacts?
How many electrons are in an atom of calcium (Ca)?
20
If I mash a potato, is it a chemical or physical change?
Physical
What is the center of an atom called?
Nucleus
Water is 2 hydrogen atoms and 1 oxygen bonded together. What type of substance is water?
Compound
A chemist mixed 20g of sodium with some chlorine. This made 30g of salt. How much chlorine reacted?
10g
How many neutrons are in an atom of Xenon (Xe)?
77
Where can you find atoms?
In anything that is matter.
What 2 parts of an atom are found in the nucleus?
Proton and neutron
Salt water is a mixture of salt and water. How could you make this mixture into a compound?
Remove either the salt or the water.
Dry the water away, or purify the water.
A chemist put 10g of sodium bicarbonate into a beaker, and added 5 g of acetic acid. The mixture reacted, and then the chemist measured the beaker. After the reaction, there was only 7g. Explain how this happened.
5
What are 2 signs that a chemical change has happened?
Change in color
Change in temperature
A solid or a gas forms (precipitate or bubbles)
A change in smell