Answer:
The volume of helium at 25.0 °C is 60.3 cm³.
Explanation:
In order to work with ideal gases we need to consider absolute temperatures (Kelvin). To convert Celsius to Kelvin we use the following expression:
K = °C + 273.15
The initial and final temperatures are:
T₁ = 25.0 + 273.15 = 298.2 K
T₂ = -196.0 + 273.15 = 77.2 K
The volume at 77.2 K is V₂ = 15.6 cm³. To calculate V₁ in isobaric conditions we can use Charle's Law.

Answer:
Collecting data
Step-by-step explanation:
During the observation phase of the scientific method, scientists are collecting data.
They can't create graphs or perform calculations, because they are still collecting data, nor can they report results to a colleague, because they have none to report.
Chemical property is when it's observed during a reaction in which the chemical composition or identity of the substance is changed. physical properties is when properties that do change the chemical nature of matter.
example for this is smell, color, freezing point, etc.