Variables
What is an independent variable in an experiment?
a variable that can stand alone, what was manipulated, changed, or added in.
The independent variable is the variable that is manipulated or changed by the researcher.
What is a hypothesis?
A hypothesis is a testable statement or prediction about the relationship between two or more variables.
What is the purpose of a control group in an experiment?
The control group serves as a baseline comparison to the experimental group, allowing researchers to determine the effect of the independent variable.
In a study testing the effect of sleep on memory, what could be a controlled variable? Why would you want to use validation therapy rather than reality orientation for a patient with dementia??
A controlled variable could be the age of the participants or the type of material being memorized.
What should you do first before mixing chemicals in the lab?
Read instructions carefully first.
Atoms are the ________ unit of matter.
What is the smallest?
Protons are _____________________ charged and found in the ________ of the atom.
What is positive/nucleus?
A chemical compound is formed by the chemical combination of two or more elements in ________ proportions.
What are definite?
A water molecule is polar because of an uneven distribution of ________.
What are charges?
The pH scale ranges from 0 to 14 and indicates the concentration of ______ ions in a solution.
What are hydrogen?
What is the dependent variable in an experiment?
The dependent variable is the variable that is measured or observed in response to changes in the independent variable.
What is the difference between an experimental hypothesis and a null hypothesis?
An experimental hypothesis predicts a relationship or effect between variables, while a null hypothesis states that there is no relationship or effect.
In an experiment, what is the role of the experimental group?
The experimental group is the group that receives the treatment or condition being tested (the independent variable).
In an experiment testing if listening to music affects concentration, what is the experimental group?
The experimental group is the group of participants who listen to music while trying to concentrate.
What is the rule about long hair in the lab?
Keep it tied up
The Greek word "atomos" means "________ __ ___."
What is "unable to cut"?
Neutrons have a ___________ charge and are also found in the ________.
What is neutral/nucleus?
Ionic Bonds are formed between?
What are Nonmetals and metals?
Cohesion refers to the attraction between molecules of the ______ substance.
give example
What is same?
stick bug on water
Solutions with a pH below 7 are called ______.
What are acids?
In an experiment testing how different amounts of sunlight affect plant growth, what would be the independent variable?
The independent variable is the amount of sunlight the plants receive.
Write a null hypothesis for an experiment testing whether exercise affects sleep quality.
The null hypothesis is that exercise has no effect on sleep quality.
Describe a scenario where a control group would be essential in determining the effect of a new medication.
A control group is essential in a scenario where one group receives the new medication, and the control group receives a placebo. This allows researchers to determine if the medication has a real effect compared to no treatment.
Explain how you would determine if a new drug is effective in lowering blood pressure using a control group.
To determine effectiveness, you would compare the blood pressure of participants who took the new drug (experimental group) with those who took a placebo (control group). A significant difference in blood pressure between the two groups would suggest the drug's effectiveness.
When handling chemicals, what should you always do to prevent contamination?
Keep chemicals properly sealed and uncontaminated.
Elements consist entirely of one type of ______.
What is atom?
A carbon atom has an atomic number of 6 and a mass number of 14.
Question: How many protons, neutrons, and electrons does a carbon-14 (C-14) atom have?
What are 6 protons, 8 neutrons, and 6 electrons?
Covalent Bonds are formed when electrons are ________ between atoms.
What is shared?
Adhesion refers to the attraction between molecules of ______ substances.
give example
What is different?
water and straw
Solutions with a pH above 7 are called ______.
What are bases?
In an experiment testing how different amounts of sunlight affect plant growth, what would be the dependent variable?
The dependent variable is the growth of the plants, typically measured in height or biomass.
Write an experimental hypothesis for an experiment testing whether studying with music improves test scores.
The experimental hypothesis is
If a person studies more, than their test scores will improve
What might happen if a researcher does not include a control group in an experiment?
Without a control group, it becomes difficult to determine whether the observed effects are due to the independent variable or other factors.
Why might it be important to have more than one controlled variable in an experiment?
Having multiple controlled variables ensures that other factors do not influence the results, allowing the researcher to isolate the effect of the independent variable on the dependent variable.
When heating chemicals in a test tube, how should you move the test tube through the flame?
Move the test tube slowly and deliberately through the flame at an angle.
The atomic number is defined by the number of ________.
What are protons?
An oxygen atom has an atomic number of 8 and a mass number of 16.
Question: How many protons, neutrons, and electrons does an oxygen-16 (O-16) atom have?
What are 8 protons, 8 neutrons, and 8 electrons?
The bond most likely to form between two oxygen atoms (O) is _________.
What is covalent?
A mixture is composed of two or more elements or compounds that are __________ mixed but not ______ combined.
Also give an example
What is physically/chemically?
What is trail mix?
Acids release ______ ions (H+) when dissolved in water.
give an example of an acid
What are hydrogen?
lemon Juice
What is a controlled variable, and why is it important in an experiment?
A controlled variable is any variable that is kept constant throughout the experiment. It is important to ensure that the results are due to the manipulation of the independent variable and not other factors.
Why must a hypothesis be testable?
A hypothesis must be testable so that it can be supported or refuted through experimentation and observation, allowing for scientific conclusions to be drawn.
How does random assignment help improve the validity of an experiment?
Random assignment reduces bias by ensuring that each participant has an equal chance of being placed in the control or experimental group, which helps ensure that the groups are similar at the start of the experiment.
How would you design an experiment to test whether drinking water before a test improves performance? Include the independent variable, dependent variable, control group, and hypothesis.
What should you do if a large chemical spill occurs?
Let the teacher handle larger spills.
Isotopes are identified by their ______ number.
What is mass number?
A sodium atom has an atomic number of 11 and a mass number of 23.
Question: How many protons, neutrons, and electrons does a sodium-23 (Na-23) atom have?
What are 11 protons, 12 neutrons, and 11 electrons?
Identify the type of bond and explain why it forms between magnesium (Mg) and oxygen (O). Magnesium has 2 electrons in its outermost shell and is a metal, and oxygen needs 2 more electrons to fill its outer shell and is a nonmetal.
What is an ionic bond? Magnesium (Mg) transfers its 2 outermost electrons to oxygen (O), which needs 2 electrons to fill its outer shell
When salt (NaCl) is dissolved in water, it forms a ________________. Identify the solute and the solvent in this solution
What is solution/salt (NaCl) as the solute/water as the solvent?
Bases release ______ ions (OH-) when dissolved in water.
Give an example of a base
What are hydroxide?
bleach