"the quantity is" is a perfectly acceptable phrase in written English.
You can use it any time you want to express the amount of something. For example, "The quantity is too large for us to manage."
"The quantity is inadequate," he said.
But the quantity is not sufficient".
The quantity is the entropy of the liquid at temperature.
The quantity is the entropy generated due to irreversibility.
The quantity is known as the para-Hermitian conjugate of the polynomial.
For many situations of practical interest, the quantity is still known mainly through experiments.
The quantity is the mass-weighted entropy at state, which is at temperature.
The quantity is the entropy of the gas (vapor) at temperature.
Principal Findings: We show that the quantity is a valid predictor in structured populations only when size is infinite.
His 182 yards against Green Bay gave him 455 through the first four games, although the quantity is not what has made the yards special.
What's more, the share of subsidised - or "affordable" - homes in the total built across Greater London is one thing, the quantity is another.
