CHEMISTRY Flashcards
(37 cards)
What are protons
Have a positive charge
Found in the nucleus
What are neutrons
Have no electrical charge
Same mass as protons
Found in nucleus
What are electrons
Surround the nucleus
Have negative charge
Located on the outside of the atom
What is a nucleus
Found in the middle of atom
Made up of protons and neutrons
What is the mass number
Located in the top left corner
Number of protons and neutrons
BIGGER NUMBER
Atomic number
Located in the bottom left corner
Number of protons only
Same number as electrons
(SMALL NUMBER)
How to calculate problems
The number of neutrons= atomic mass-atomic number
Eg) FLURINE= 19-9
= 10 neutrons
What is atomic mass
Protons + neutrons
What is the atomic number
Just the protons
Rules for atomic number problems
Atomic number is no. Of protons
Mass no. Is no. Of protons and neutrons
No. Of protons is the same as the first column
No. Of neutrons is the first column minus the second column
No. Of electrons is the mass no. Minus the atomic number
How do u know if a chemical reaction has taken place
Smell
Sound
Colour
Smoke
How is radioactivity caused
If neutrons and protons in an isotope are not together they are unstable and can break into other elements
What is an isotope
Different forms of an element
Share the same no. Of protons but different no. Of neutrons
Same atomic number but different atomic mass
How to pick an isotope
Look for the same atomic number but different mass number
What are the three different types of radioactivity
Alpha (a)
Beta (B)
Gamma (y)
Alpha particles
Contain 2 protons and 2 neutrons
Positively charged
Can’t travel easily
Can be stopped by paper or human skin
Beta particles
Same size and mass as electrons Negative or positive charge Can travel at the speed of light Can penetrate human skin Can't penetrate plastic, wood or aluminium
Gamma rays
Came after alpha and beta particles
Travel at speed of light
Cause damage to living tissue
Stopped by lead or concrete
Ionic bonding
Chemical bond between a metal iron and non-metal ion
Metal atom loses electron to form a Cation
Non-metal atoms gains electrons to form anion
Chemical formula for ionic compounds
Write name of metal first
Write name of non metal second
Replace the end of the non metal with ‘ide’
How to solve an ionic formula
Cross solve by taking the metal ion to the bottom of the non metal and the non metal across to the metal
How to identify reactant from product
New substances formed= product
Original substance= reactant
What do chemical reactions involve
Re-arrangements or atoms
Breaking bonds
What is the law of conservation
Any atoms represented in the reactants must be present in the products
Matter can’t be created or destroyed
