Because they are composed of the very same atoms. There is no difference between their composition, and hence there can be no difference in the way they react.
Atoms of the same element have no personalities or individuality; they will always behave the same (given all other conditions are also equal).
Not necessarily. The temperature of the samples would have to be the same. It can also vary with how pure the substance is.
Pure substances have identical particles. This means that all samples of a pure substance will have the same type and arrangement of particles, whether they are atoms, molecules, or ions. Examples of pure substances include elements and compounds.
The properties of a pure substance do not vary from sample to sample because there is no reason for them to. Why would they? Water is water, and if you take any sample of water from any stream, lake or ocean and remove all the "stuff" in it to leave only the water, all the samples will behave the same way physically and chemically. The chemical properties of a substance (and the physical ones, too) are set by what the substance is. And these properties define the way the substance behaves in the universe as a whole. There is no reason for any water found on, say Mars, to behave any differently than any water here on Earth - or anywhere else in the universe.
A pure substance consists of only one type of element or compound. The composition of a pure substance always stays the same, with a fixed ratio of its constituent particles.
A pure substance in which all the atoms have the same atomic number or number of protons is an element.
Density is simply the mass divided by volume. This means that it is the amount of the substance in a specific unit of space. Because a pure substance indicates that it is exactly that, a substance made of a specific combination of elements, it will always have the same density because those elements can only take one form in order for it to be pure.
Not necessarily. The temperature of the samples would have to be the same. It can also vary with how pure the substance is.
Dalton's atomic theory states that elements consist of indivisible particles called atoms and that atoms of the same element are identical in size, mass, and properties. Therefore, every sample of a pure substance will have the same properties because each sample is made up of the same type of atoms arranged in the same way.
Yes, all homogeneous matter can be classified as a pure substance because it has a uniform composition throughout. This means that all samples of the matter have the same properties and composition, making it a pure substance.
The density of pure aluminium is the same for all samples.
Pure substances have identical particles. This means that all samples of a pure substance will have the same type and arrangement of particles, whether they are atoms, molecules, or ions. Examples of pure substances include elements and compounds.
The properties of a pure substance do not vary from sample to sample because there is no reason for them to. Why would they? Water is water, and if you take any sample of water from any stream, lake or ocean and remove all the "stuff" in it to leave only the water, all the samples will behave the same way physically and chemically. The chemical properties of a substance (and the physical ones, too) are set by what the substance is. And these properties define the way the substance behaves in the universe as a whole. There is no reason for any water found on, say Mars, to behave any differently than any water here on Earth - or anywhere else in the universe.
Any sample size of a particular substance will have the same density.
Two different samples of a pure substance would have the same physical properties, such as color, melting point, boiling point, and density. Their chemical properties, like reactivity and ability to form specific compounds, would also be identical. Variations in the samples' properties could indicate impurities present.
Because they are of the same substance they have the same density density = mass/volume
A pure substance consists of only one type of element or compound. The composition of a pure substance always stays the same, with a fixed ratio of its constituent particles.
The answer is: No. Density is a property of a substance, and doesn't depend on the size of the sample. Samples of different sizes all have the same density, as long as they're all samples of the same substance, their compositions are all the same, and the conditions are the same in every case. (Samples of ice and water have different density, because the conditions are different.)