PAPER 1 - QUIZ

Question 1

What is the difference between elements, mixtures and compounds?

Answer 1

element : a substance made from one type of atom
compound : a substance made from one or more types of atoms chemically bonded together
mixture : a substance made from elements and/or compounds not chemically bonded

Question 2

How do you get pure water from a salt solution/sea water?

Answer 2

Use distillation: evaporate the water 9the solvent) and condense it back into a liquid, leaving the salt (solute) behind.

Question 3

Describe the three states of matter: solid, liquid, gas

Answer 3

Solid : particles in regular arrangement, and vibrate about fixed positions
liquid : particles have no regular arrangement and are able to move past each other
gas : particles are far apart, move randomly at fast speeds (high energy)

Question 4

what did Rutherford discover about atoms, and how?

Answer 4

He discovered the nucleus by firing alpha particles (positive charge) towards a thin gold leaf. Most went straight through; some were deflected. This showed that every atom is mostly empty space, but a small positive charge at the centre - the nucleus

Question 5

relative charge for …..
proton,neutron,electron
relative mass for …..
proton,neutron,electron

Answer 5

relative charge:
+1,0,-1
relative mass:
1,1,0 (very small)

Question 6

what do metals always do when they bond (ionic bonding) ?

Answer 6

metals donate their outer electron (s) to leave an empty outer shell

Question 7

non - metals can take part in ionic bonding or covalent bonding. what is the difference?

Answer 7

ionic:
non-metals accept electrons from metals to form ions
covalent:
non-metals share electrons to gain full outer shells

Question 8

What are the alkali metals, and how do their reactivities vary?

Answer 8

make an alkali when reacted with water. donate 1 electron to leave empty outer shell: +(1) ions. Reactivity increases down group as outer electron removed more easily due to being further from the nucleus

Question 9

What are the halogen gases, and how do their reactivities vary?

Answer 9

form -(1) ions by accepting an electron to gain full outer shell. Reactivity increases up the group due to the electron being accepted more easily when outer hell is closer to nucleus.

Question 10

What is the word equation for a fuel cell?

Answer 10

O2 + 4H+ + 4e- → 2H2O.

Question 11

What are the Electrode half equations for fuel cells?

Answer 11

At the negative electrode:
2H2 + 4OH- → 4H2O + 4e-

At the positive electrode:
O2 + 2H2O + 4e- → 4OH-