ATOMIC STRUCTURE
This particle has a positive charge and is found in the nucleus.
What is a proton?
Atoms of the same element with different numbers of neutrons are called:
What are isotopes?
Balance:
H₂ + Cl₂ → HCl
H₂ + Cl₂ → 2HCl?
These are the substances present before a reaction occurs.
What are reactants?
The atomic number tells us the number of these particles.
What are protons?
An atom has 11 protons. This number tells us its ________.
Atomic Number
This type of radiation consists of 2 protons and 2 neutrons.
What is an alpha particle?
Balance:
Mg + O₂ → MgO
2Mg + O₂ → 2MgO?
These are the substances formed during a reaction.
What are products?
The mass number equals the number of protons plus:
Neutrons
This scientist used the gold foil experiment to change our understanding of the atom.
Who is Rutherford?
A radioactive isotope becomes more stable by undergoing this process.
What is radioactive decay?
Balance:
N₂ + H₂ → NH₃
N₂ + 3H₂ → 2NH₃
Why must chemical equations be balanced?
To follow the Law of Conservation of Mass.
A neutral magnesium atom has 12 protons. How many electrons does it have?
12 electrons
An atom has 17 protons. Which element is it?
What is Chlorine?
Polonium-210 emits an alpha particle and becomes Lead-206. What happened to the mass number?
What is "it decreased by 4"?
True or False:
You can change subscripts when balancing equations.
False
A sealed flask weighs 100 g before a reaction and 100 g after. Which scientific law does this demonstrate?
What is the Law of Conservation of Mass?
An element has atomic number 17 and mass number 35. How many neutrons does it have?
18
A student says, "The nucleus takes up most of the atom." Explain why this statement is incorrect.
The nucleus is tiny and dense; most of the atom is empty space.
Two carbon atoms both have 6 protons, but one has 6 neutrons and the other has 8 neutrons. What are these atoms called?
What are isotopes?
Balance:
Al + O₂ → Al₂O₃
4Al + 3O₂ → 2Al₂O₃
When magnesium burns in oxygen, why does the mass of the magnesium oxide produced end up greater than the mass of the magnesium alone?
Oxygen atoms are added to the magnesium during the reaction.
A student balances an equation by changing H₂O into H₃O. Explain why this is incorrect.
You can only change coefficients, not chemical formulas.