Scientific Thinking
What represents the beliefs of most scientists based on evidence and repeated investigation?
Answer: What is scientific consensus?
What branch of science studies matter and energy?
Answer: What is physical science?
What two particles are found in the nucleus of an atom?
Answer: What are protons and neutrons?
Which scientist discovered that atoms contain smaller negatively charged particles called electrons?
Answer: Who is J. J. Thomson?
How many valence electrons does bromine have?
Answer: What is 7?
Why is it important for scientists to repeat one another's work?
Answer: What is to identify possible errors and reduce the effects of bias?
What type of mixture has components that can be separated by physical processes?
Answer: What is a mixture?
What negatively charged particle is found outside the nucleus?
Answer: What is an electron?
What did Thomson's cathode ray experiment demonstrate about atoms?
Answer: That atoms can be divided into smaller parts and contain electrons.
Which family contains very reactive nonmetals?
Answer: What are the halogens?
Which type of scientific knowledge is most likely to be modified or discarded when new evidence does not support it?
What is a hypothesis?
A mixture has different ratios of its component substances in different portions. What type of mixture is it?
Answer: What is a heterogeneous mixture?
Where is most of an atom's mass concentrated?
Answer: What is the nucleus?
Which scientist's model showed that an atom has a small, dense nucleus?
Answer: Who is Ernest Rutherford?
Which family generally does not react naturally with other elements?
Answer: What are the noble gases?
Scientists use these to represent complex ideas or objects that may be difficult to study directly.
Answer: What are scientific models?
What is the difference between a compound and an element?
Answer: A compound contains two or more elements in a fixed proportion, while an element contains only one type of atom.
Two atoms are isotopes of the same element. What must they have in common?
Answer: They must have the same number of protons.
How was Bohr's atomic model different from Rutherford's?
Answer: Bohr's model showed that electron orbits had distinct radii/energy levels.
Why was Mendeleev's periodic table better accepted than other systems of his time?
Answer: Because it could accommodate elements that had not yet been discovered.
Put these scientific-method steps in the correct order: analyze data, ask questions, form a hypothesis, conduct an investigation, draw a conclusion.
Answer: Ask questions → form a hypothesis → conduct an investigation → analyze data → draw a conclusion.
A substance has a mass of 27.3 g and a volume of 7.0 cm³. What is its density?
Answer: What is 3.9 g/cm³?
Formula: Density = Mass ÷ Volume
An element has two isotopes: X-63 has a mass of 62.9296 amu and is 69.15% abundant. X-65 has a mass of 64.9278 amu and is 30.85% abundant. What is the average atomic mass?
Answer: What is 63.55 amu?
Why did scientists change atomic models over time?
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Answer: Because new experimental evidence led scientists to modify their understanding of the atom
What property did Moseley use to arrange the elements more accurately?
Answer: What is atomic number?