Scientists use the scientific method all the time to help them understand things about certain topics. The scientific method is a list of steps that are used before, during, and after the experiment. The scientific method can help prove hypothesis about things and can tell you the outcome of the experiment.
Answer:
a.
Explanation:
At 28 degrees highest line is CaCl2. Answer a.
Answer:
Gravitational force of attraction.
Explanation:
When two bodies of masses 'm' and 'M' are separated by a distance 'r', then both the bodies experience a force of attraction towards each other. This force of attraction is called gravitational force. It is a weak force but it always act between two bodies that have mass.
The magnitude of the gravitational force is directly proportional to product of the masses and inversely proportional to the square of the distance between the masses.
This means that as the distance between the bodies is increases, the gravitational force between the bodies decreases and vice versa.
The gravitational force of attraction is given as:

<span>CH4 + 2O2 --> CO2 + 2H2O </span>
Answer:
666,480 Joules or 669.48 kJ
Explanation:
We are given;
- Volume of water as 2.0L or 2000 ml
but, density of water is 1 g/ml
- Therefore, mass of water is 2000 g
- Initial temperature as 20 °C
- Final temperature as 99.7° C
Required to determine the heat change
We know that ;
Heat change = Mass × Temperature change × specific heat
In this case;
Specific heat of water is 4.2 J/g°C
Temperature change is 79.7 °C
Therefore;
Heat change = 2000 g × 79.7 °C × 4.2 J/g°C
= 669,480 Joules 0r 669.48 kJ
Thus, the heat change involved is 666,480 Joules or 669.48 kJ