[Dr.So0oMa]

مَسَاكُمْ صَبَاحُكُمْ خَيْرٌ


^^

عِنْدِيْ طَلَبٌ بْلَيْزَ
الاسْئِلَةِ التَلاتِهُ دَيَّ مَا فَهِمَتهاا
عَ ايّ اسَاسَ اخْتَارَ الْجَوَابُ

* دا مِنْ شبُتّرِ 1 تَسْتَ بِانَّكَ بَارَتْ وَنَ لِلْاحْيَاءِ

16) To be scientifically valid, a hypothesis must be
A) phrased as a question.
B) based on faith.
C) controlled.
D) reasonable.
E) testable and falsifiable.
Answer: E
Topic: 1.8
Skill: Conceptual Understanding

17) The role of a control in an experiment is to
A) provide a basis of comparison to the experimental group.
B) prove that a hypothesis is correct.
C) ensure repeatability.
D) prove that a hypothesis is correct and ensure repeatability.
E) counteract the negative effect of the experiment.
Answer: A
Topic: 1.8
Skill: Conceptual Understanding

18) A scientist performs a controlled experiment. This means that
A) the experiment is repeated many times to ensure that the results are accurate.
B) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.
C) two experiments are conducted, one differing from the other by only a single variable.
D) two experiments are conducted, one differing from the other by two or more variables.
E) one experiment is performed, but the scientist controls the variables.
Answer: C
Topic: 1.8
Skill Conceptual: Understanding