Question 1

Which of the following best describes the scientific method as presented in the study materials?

Accepted Answer

A flexible, iterative process that can involve revisiting earlier steps based on new findings.

Question 2

Which of the following is NOT a characteristic of a good scientific hypothesis?

Accepted Answer

It can be proven true beyond all doubt.

Question 3

A researcher observes that a certain plant grows faster in sunlight than in shade. Which step of the scientific method is this?

Accepted Answer

Making an observation

Question 4

Which four elements make up approximately 96% of living matter in the human body?

Accepted Answer

Carbon, hydrogen, oxygen, nitrogen

Question 5

Given an atom with 6 protons, 6 neutrons, and 6 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 6, Mass number: 12

Question 6

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 7

A radioactive isotope has a half-life of 10 years. If you start with 100 grams, how much will remain after 30 years? Use the formula $$N = N_0$ 	imes (\frac{1}{2}$$)^{t/T_{1/2}$$}$$ where $$N_0 is $$the initial amount, $$t is $$time, and $$T_{1/2} is $$half-life.

Accepted Answer

12.5 grams

Question 8

Which subatomic particle determines the chemical behavior of an atom?

Accepted Answer

Electrons

Question 9

How many valence electrons does carbon have, and why is this significant for its bonding behavior?

Accepted Answer

4; it allows carbon to form up to four covalent bonds with other atoms.

Question 10

Which of the following best explains why sodium (Na) and chlorine (Cl) form an ionic bond?

Accepted Answer

They have very different electronegativities, causing sodium to lose an electron and chlorine to gain one.

Question 11

Which of the following molecules contains a polar covalent bond?

Accepted Answer

Water ($$H_2O)$$

Question 12

If the electronegativity difference between two atoms is 0.35, what type of bond will they most likely form?

Accepted Answer

Nonpolar covalent bond

Question 13

Which of the following best describes the distribution of electrons in a water molecule ($$H_2O$$)?

Accepted Answer

Electrons are shared unequally, with more electron density around the oxygen atom.

Question 14

A scientist wants to test whether a new fertilizer increases plant growth. Which of the following is the best hypothesis?

Accepted Answer

"If plants are given the new fertilizer, then they will grow taller than plants without it."

Question 15

Which of the following statements about chemical bonds is correct?

Accepted Answer

Ionic bonds involve the transfer of electrons from one atom to another.

Question 16

Which of the following is a real-world application of radioactive isotopes in biology?

Accepted Answer

Carbon-14 dating of fossils

Question 17

If an atom has an atomic number of 11 and a mass number of 23, how many neutrons does it have? Use the formula $$	ext{Number of neutrons} = 	ext{Mass number} - 	ext{Atomic number}.$$

Accepted Answer

12

Question 18

Which of the following best explains why noble gases are chemically inert?

Accepted Answer

They have completely filled valence electron shells.

Question 19

A student mixes two isotopes of oxygen, $$^{16}O$$ and $$^{18}O$$, in a beaker of water. Which statement is correct?

Accepted Answer

Both isotopes are present in the water, but $$^{16}O is $$the more common form.

Question 20

Which of the following scenarios best illustrates the application of the scientific method in a non-linear fashion?

Accepted Answer

A researcher revises their hypothesis after analyzing unexpected experimental results.

Introduction to Biology and the Scientific Method

Guida di studio - Domande di pratica

Study guide - Flashcard