Art is defined differently by different people and at different times. I understand your definition differs from that of some museum curators. This does not mean that your definition should be valid for everybody else.
Matter is anything that has mass and takes up space. Mass is the amount of matter or "stuff" in a certain object. The amount of space an object takes up is its volume
No, the density is defined as the amount of mass per unit volume.
In science or chemistry or anything similar, pH is defined as the acidity content or amount within something, and so soil pH refers to the amount of acid a sample or area of soil may contain.
Matter is defined as anything that has mass and volume. Mass is the amount of matter in an object. Volume is the amount of space an object takes up.
The amount of substance per unit of volume is defined as concentration in terms of chemistry. The amount of substance refers to the quantity over the volume.
mass
which may be defined as a series of consecutive payments or receipts of equal amount.
There is over one thousand two hundred museum's of some type here's the linkhttp://www.dmf.culture.gouv.fr/mf/DMF_MF_092007.pdf
By the amount of resources the nation has
by the amount of gold a nation has...
No defined amount.
A defined benefit plan provides a set amount of benefit to the employee at the time of retirement, and a defined contribution plan specifies the amount of money an employer contributes to a retirement fund for each individual employee.