2)
1.because it is very
difficult to imagine
life without chemistry
2.meter is a unit of measure, we measu-
re
length with it
3.Electrons have a negative charge,
protons have a
positive charge, and neut-
rons have no charge.
4.protons
have a positive charge and
neutrons have no charge
3)
1.I’m
the centre of the atom, I contain
protons and neutrons. I’m the electron
2.I move around the nucleus. I’m an
nucleus
3.I’m positively charged. I’m a ion
4.I’ve no charge. I’m
a neutron
5. I’m an electrically charged atom. I’m
an electron
4)
a. How is matter?
b. How many can matter exist?
c. What of the three states of matter have
a fixed shape?
d. What of them have no fixed volume?
e.
Which
are atoms
made up of?
f. What of the constituents of an atom
are outside the nucleus?
g. How are the properties of matter clas-
sified?
h. How many kinds of atoms are there
in an element?