Answer:
A) All the elements are composed of atoms.
d) Atoms cannot be created or destroyed in any chemical changes.
c) An atom of one element cannot be changed into an atom of a different element.
Explanation:
The main postulates of Dalton atomic theory was:
1) The matter is composed of atoms and atom is indivisible particle which can not be destroyed.
2) The atoms of an element are identical.
3) The atoms of different elements are combining with definite proportion and form compounds.
4) The atoms of different elements are different from each other.
5) During chemical reaction rearrangement of atoms occur and form new compounds.
1) Solids have a fixed shape
The particles of solids are held into their positions and are only able to vibrate about fixed points. The strength of the bonding means that the particles have their own shape, which they retain, and do not take the form of the container they are in.
2) Solids may not flow
The molecules of liquids are able to slide past one another due to weaker bonds between particles. This allows the liquid to flow; whereas, this movement is not possible in solids so they cannot flow.
3) Solids may fracture
The fact that solids possess a rigid structure means that they have the ability to fracture. Although some are able to withstand more stress than others, all solids may break. This breakage occurs when the intermolecular bonds are mechanically broken. This is not possible in the case of liquids because such rigid intermolecular bonds do not exist.
Answer:
Mass of seawater = 512.5 gram
Explanation:
Given:
Volume of seawater = 500 ml
Density of seawater = 1.025 g/ml
Find:
Mass of seawater
Computation:
Mass of seawater = Volume of seawater × Density of seawater
Mass of seawater = 500 × 1.025
Mass of seawater = 512.5 gram
Answer:
D
Explanation:
Universe consits of galaxies, galaxies consit of solar systems, and solar systems consist of planets
