science test 19

Question 1

What are the key components of a well-plotted graph?

Answer 1

A clear title
Properly labeled axes with units
Evenly spaced scales
Accurate plotting of points
A best-fit line or curve (if applicable)

Question 2

What is the best way to measure an object accurately using a ruler?

Answer 2

Place the ruler flat against the object
Align the zero mark correctly
View from directly above to avoid parallax error
Use mm or cm for more precision

Question 3

What is the difference between precision, accuracy, and reliability?

Answer 3

Precision: How close repeated measurements are to each other.
Accuracy: How close a measurement is to the true value.
Reliability: How consistent results are when repeated.

Question 4

What are the key steps in planning a scientific experiment?

Answer 4

Identify the aim (what you are investigating).
Form a hypothesis.
Identify independent, dependent, and control variables.
Choose appropriate equipment and methods.
Plan how to record and analyze data.
Consider safety precautions.

Question 5

How do you calculate the average from a set of data?

Answer 5

Average = (Sum of all values) ÷ (Number of values)

Question 6

What are the positive results for common food tests?

Answer 6

Starch (Iodine Test): Blue-black
Glucose (Benedict’s Test): Green → Yellow → Orange → Red (with heat)
Proteins (Biuret Test): Purple/Lilac
Lipids (Emulsion Test): Milky-white emulsion

Question 7

How should a scientific data table be structured?

Answer 7

Title describing what the table shows
Independent variable in the first column
Dependent variable in subsequent columns
Units clearly labeled
Consistent decimal places

Question 8

How do you apply scientific knowledge to interpret data and draw conclusions?

Answer 8

Identify trends and patterns in the data
Compare results to scientific principles
Consider possible errors or limitations
Make evidence-based conclusions