Chemistry - Block 2 Flashcards
Protons and …….. are always equivalent?
Electrons
What charge does an atom have overall, and why?
Neutral because electrons and protons are always equal
What charge does a proton have ?
Positive
What charge does a neutron have ?
Neutral
What charge does an electron have ?
Negative
What is a mass number?
Protons + Neutrons
What is the atomic number ?
Number of electrons
What is the difference between elements and compounds?
Elements are a pure substance containing only one type of atom and compounds are formed by two or more different elements
What are atoms ?
The smallest part of an element
What are Isotopes
An atom with the same number of protons but different number of neutrons
What is filtration ?
Separates insoluble particles from liquids
What did John dalton suggest atoms where ?
Solid spheres
Who discovered the atom
JJ Thompson
How were elements ordered in the original periodic table ?
Order of Atomic weight
Why did Mendeleeves leave gaps in the periodic table?
For undiscovered elements
How are elements on the periodic table ordered now ?
Ordered by increasing atomic mass
What does group one metals also mean ?
Alkali Metals
What does group seven elements mean ?
Halogens
What does group zero elements mean ?
Noble Gases
Why is group 0 not called group 8 ?
As all of them have a full outer shell of 8 on electronic configuration, but Helium which only has 2
How does lithium react with water ?
Releases Hydrogen, floats and fizzes on water
How does sodium react with water ?
Releases Hydrogen, moves fast along water and turns into a sphere
How does potassium react with water ?
Releases Hydrogen, purple flame, explodes
Where are electrons found ?
On the electron shell
