Atoms Flashcards
How many known atoms are there?
There are 118
How do scientists see atoms?
Scientists use a scanning tunnelling microscope (STM) to see an atom because atoms are so small you can’t use a normal microscope.
How many atoms are found naturally?
Only 91 atoms are found naturally on Earth.
When atoms stick together what do they form?
Molecules or crystal lattices
If a substance is made up of just one atom what is it called?
It is called an element
What is the one non-metallic element that form…
Carbon is the only non-metallic element that can form crystal lattices
What is a compound?
If a substance is made up of molecules or a crystal lattice with different types of atoms it is called a compound.
Compounds can be both molecules or crystal lattices, but which is more common?
Many compounds are crystal lattices
Atoms are made up of even smaller particles known as…
Subatomic Particles
Name the 3 subatomic particles
Protons, neutrons and electrons.
The protons and neutrons form a cluster that sits at the centre if the atom, this cluster is known as the..
Nucleus
Protons and neutrons are similar in size, how big/small are the electrons?
Electrons are approximately 1800 times smaller than protons and neutrons and HAVE A NEGATIVE CHARGE.
Are protons positively or negatively charged?
Positive
Do opposite electric charges attract each other? And give an example.
Yes, the negatively charged electrons causes it to be attracted to the positively charged protons.
The number of protons in the nucleus define the…
Type of atom.
What is the atomic number?
How many protons are in the nucleus
What is the mass number?
Total number of protons and neutrons in the nucleus
What is an isotope?
Atoms that have the same number of protons but different number of neutrons
What Rutherford find out about atoms?
Rutherford found that atoms are are made up of mostly empty space
How are the electrons attracted to the nucleus and why do they never fall into the nucleus?
Electrons are attracted to the protons positive charge. Electrons are trapped in electron shells which means they will never fall into the nucleus
How many electrons can the 1st shell hold?
2 electrons
How many electrons can the 2nd shell hold?
8 electrons
How many electrons can the 3rd shell hold?
18 electrons
How many can the fourth electrons shell hold?
32 electrons
What is an atom?
unit of matter
What does diatomic mean?
A molecule containing two atoms
