Physics: Describing Atoms Flashcards
What are the three main subatomic particles of an atom?
Protons, neutrons, electrons
These particles make up the structure of an atom.
What is the radius of an atom?
Around 1×10^-10 metres
Atoms are incredibly small.
What is the charge of the nucleus of an atom?
Positively charged
The nucleus contains protons and neutrons.
Where are electrons located in an atom?
Orbiting outside the nucleus
Electrons are much smaller than protons and neutrons.
What particles are found in the nucleus of an atom?
Protons and neutrons
The nucleus is the central part of the atom.
What charge do protons have?
Positive charge
Protons are one of the key components of the atomic nucleus.
What is the charge of neutrons?
No charge (neutral)
Neutrons contribute to the mass of the nucleus but not to its charge.
What charge do electrons have?
Negative charge
Electrons are responsible for chemical bonding.
Fill in the blank: Each particle of an atom has its own ______ and its own mass.
charge
This distinguishes the different subatomic particles.
What charge does a proton have?
+1
What is the relative mass of a proton?
1
What charge does a neutron have?
0
What is the relative mass of a neutron?
1
What charge does an electron have?
-1
What is the relative mass of an electron?
1/1835
What particles make up most of the mass of an atom?
Protons and neutrons
What defines the element of an atom?
The number of protons
What is the mass number?
The total number of protons and neutrons
What is the atomic number?
The number of protons
What is another name for mass number?
‘Nucleon number’
Mass number can also be called ‘nucleon number’.
What is another name for atomic number?
‘Proton number’
Atomic number can also be called ‘proton number’.
In a neutral atom, how do the number of electrons and protons compare?
They are always the same.
What happens to the number of electrons in an ion?
It changes; an ion has lost or gained one or more electrons.
What did most people in ancient Greece believe matter was made of?
Most people believed matter was made up of combinations of four elements: earth, air, fire, and water.
Who was the ancient Greek philosopher that proposed the idea of uncuttable pieces of matter?
The philosopher Demokritos (460-370 BCE) thought that matter was made up of millions of tiny, uncuttable pieces.
What does the word ‘atom’ mean?
The word ‘atom’ comes from the word ‘atomos’, which means uncuttable.
What are isotopes?
Isotopes are forms of an element that have the same number of protons but different numbers of neutrons.
What are three ways to give electrons energy?
Light, Electricity, Heat
What happens if an electron absorbs lots of energy?
If an electron absorbs enough energy, it can leave the atom completely. This makes the atom an ion.
What happens when atoms absorb energy?
Electrons at a particular level are pushed up to higher levels, becoming ‘excited’.
What occurs after electrons become excited?
They eventually jump back down to a lower level, releasing the energy as an electromagnetic wave
