1.matter is made up of small particles
2.particles of matter are in constant random motion
Explanation:
1.Particles eg of salt can be crashed into smaller particles 2.When you sprinkle pollen grains on water in a beaker and observe using a hand lens U'll see they are moving randomly
Explanation:
The atomic spectrum is more like the transitions of electrons among electronic energy levels in an isolated atom. Atomic spectrum is mainly affected by interaction of the transitioning electrons between the nuclei spins and between the other electrons in the same atom.
However, molecular spectrum involve transition of electrons in molecules with two and more atoms(it can be in the same or different). Also, the valence electrons are now in different orbitals than that of the atomic orbitals and the orbital structure has changed the electronic transitions are different
Flourine
Explanation:
The element F has a high negative (ΔeqHө) but not so high IE1 . Therefore, it is the least reactive non-metal.
B is the answer
<span>least 20 characters </span>
The atomic number=5
The mass number=11
<h3>Further explanation</h3>
In the following element notation,

X = symbol of elemental atom
A = mass number
= number of protons + number of neutrons
Z = atomic number
= number of protons = number of electrons, on neutral elements
So for The atomic notation for a particular atom of Boron :
₅B¹¹
Z=5=atomic number
A=11=mass number