Scientific method
“An observation using numbers (like ‘the plant grew 4.5 cm’)
What is a quantitative observation?
“Mass divided by volume (D = m ÷ V).”
What is density?
“The number that equals the count of protons in the nucleus and identifies the element.”
What is the atomic number?
“A bond formed by transferring electrons from a metal to a nonmetal.”
What is an ionic bond?
“Which unit covers density and measurement?”
What is Unit 2 (Matter)?
“The testable ‘If…then…’ statement you make before running an experiment.”
What is a hypothesis?
“A change where one or more new substances form (examples: burning, rusting).”
What is a chemical change?
“Atoms of the same element with different numbers of neutrons are called _____.”
What are isotopes?
What is an ionic bond?
What is a covalent bond?
“Name one macromolecule that stores genetic instructions.”
What is nucleic acid (DNA)?
“The factor the experimenter deliberately changes.”
What is the independent variable?
"A change of state from liquid to gas (example: boiling).”
What is evaporation?
“Outermost electrons used in bonding are called _____. ”
What are valence electrons?
“A shorthand diagram that shows valence electrons as dots around the element symbol.”
What is a Lewis dot structure?
“Give one real‑world example where water’s high specific heat matters
What is ocean moderating climate? or any correct answer
What is the independent variable?
What is the control group?
“Mass = 54 g and volume = 18 mL. This is the object’s density (g/mL).”
What is 3.0 grams per milliliter?
“If an element has atomic number 16 and atomic mass 32, this is the number of neutrons.”
What is 16?
“Chlorine has 7 valence electrons. According to the octet rule, it’s most likely to _____ one electron to become stable.”
What is gain? (or what is gain 1 electron)
“A student measures mass before reaction 250 g, after reaction 238 g in open beaker — fastest explanation?”
What is gas escaped (mass left as gas)?
A bar graph shows plant heights: 0 g = 12 cm, 5 g = 18 cm, 10 g = 22 cm, 15 g = 20 cm. This amount produced the greatest average height.
What is 10 grams?
“Name one clear sign that a chemical reaction occurred in a lab"
(list any one: e.g., gas, color change, precipitate, temp change).”
“This vertical arrangement on the periodic table groups elements with similar chemical properties.”
What is a group (or family)?
“Draw or describe the Lewis dot structure for oxygen (O). How many valence electrons does it show?”
Correct response: What is 6 valence electrons (O with six dots)?
“Using F = ma, calculate acceleration: net force 12 N, mass 3 kg. (show the number).
What is 4 m/s²?