Physical Revision Flashcards
List the characteristics of metals (CSMSDD)
- Good electricity and heat CONDUCTORS
- Shiny
- Malleable
- Sonorous
- Ductile
- DENSE (usually) high melting/ boiling point (usually)
Distinguish between period and group in periodic table 3
Period- horizontal row
Group- vertical column (typically have similar properties)
On the periodic table, where can you find:
- Alkali metals
- Alkali earth metals
- Transition metals
- Halogens
- Inert gases (type of noble gases)
- Metalloids
- Non-metals
Alkali – group 1 (far left)
Alkali earth – group 2
Transition – between 2 and 3
Halogens – group 7
Inert gases – group 8 (far right)
Metalloids, diagonal line from bottom right
Non metals – top right triangle including G7,8
What are the key trends as you move down group 1 metals?
- More reactive
- More dense
- Softer
- MP BP decrease
Describe reaction of group 1 with water
- Effervesce – produces hydrogen - burns
- Metal hydroxide solution (goes lilac with phenolphthalein alkali indicator)
- Lithium-red
- Sodium-yellow
- Potassium - lilac
What’s the structure of an atom?
- Protons + neutrons in nucleus
2. Electrons in shells around nucleus
Charge and mass of particles in an atom?
Proton – positive – 1 mass unit
Neutron – neutral – 1 mass unit
Electron – negative – 1/1800 mass unit
How does atomic number and mass relate to protons neutrons and electrons.
Atomic number = no of protons (or electrons in atom)
Atomic mass = no of protons + no of neutrons.
Describe this atom: 37 on top, 17 on bottom, Cl
Chlorine – 17 protons, 20 neutrons, 17 electrons.
What is an isotope?
An isotope is an element with same number of protons and different neutrons.
Atomic number must be the same, mass different.
Write another isotope of chloride: 37 on top, 17 on bottom, Cl
h
How many naturally occuring isotopes of chlorine are there?
2- chlorine 37 and 35. It is 75% 35 and 25% 37, thus its’ average atomic weight is 35.5 amu
What is net charge of an atom? How do you find it?
Net charge- If an atom has an equal number of protons and electrons, its net charge is 0. If it gains an extra electron, it becomes negatively charged and is known as an anion. If it loses an electron, it becomes positively charged and is known as a cation.
How to find net charge- To calculate the net charge, simply add the number of protons then subtract the number of electrons. Most often you’ll find the net charge of an atom is zero.
Explain why different elements in the same group react in the same way
The number of electrons in the outer shell determines chemical properties.
Eg group 1 has 1 electron in outer shell and want to lose that electron to get a stable outer shell configuration
Explain why noble gasses are unreactive
They have 8 electrons in outer shell and do not need to lose or obtain electrons to get stable configuration 8
