Chemical changes and structure

• What is the test for oxygen?


  it relights a glowing splint.
• What is the test for CO2?

  It turns limewater milky.
• What is the test for Hydrogen?

  It burns with a POP!!
• What is the formula for rates of reaction?

  Average Rate = ^q/^t
• What are the factors that affect the speed of a reaction?

  decrease particle size, increase concentration, increase temperature, catalyst
• why do elements within a group share the same valency and have similar chemical properties?

  Elements within a group share the same valency and have similar chemical properties

  because they have the same number of electrons in their outer energy levels.
• What do protons have a charge of?

  +1
• What do neutrons have a charge of?
• What do neutrons have a charge of?

  0
• What do electrons have a charge of?

  -1
• what is the mass of a proton?

  1
• What is the mass of an electron?

  0
• What is the mass of a neutron?

  1
• what does the No. of protons equal?

  no. of protons = no. of electrons = atomic no.
• why is an atom neutral?

  an atom is neutral because there is the same no. Of positively charged protons and negatively charged electrons.
• How to find the mass no.

  Mass No. = No. of protons + No. of neutrons.