C3 - Atoms, Elements, and Compounds Flashcards
Define element.
Contains only one type of atom
Define atom.
Smallest particles of matter, we cannot break them down further by chemical means
Define compound.
Different atoms bonded together (chemically joined)
Define mixture.
A sample with different atoms or molecules - not chemically bonded, they can be separated by physical means
What is a group?
Vertical columns.
What is a period?
Horizontal rows.
What is in the nucleus of an atom?
protons and neutrons.
Where are the metals in the periodic table?
left side.
In a neutral atom, what two particles have the same number?
protons and electrons.
What is the atomic number?
The number of protons (and electrons) in the nucleus. ege. carbon = 6
What is the mass number?
The amount of protons and neutrons as the both weigh roughly 1 a.m.u. (atomic mass unit) e.g. carbon = 12
What are the different energy levels in an atom called?
Shells.
What are isotopes? [3]
- Isotopes have the same number of protons but different numbers of neutrons. They are the same element but have some different properties.
- They have the same arrangement of electrons, so the same chemistry.
- They have more neutrons, so more mass, this changes their density.
What is half-life?
the time taken for the radioactivity of a specified isotope to fall to half its original value.
Name 3 uses of radiation.
Medical.
Fuel.
Carbon dating.
