Atoms
This subatomic particle is located in the middle of the atom and is positive
Proton
Which element has 43 protons?
Tc Technentium
On a periodic table, what are the vertical columns called?
Groups
Which statement best explains why scientific knowledge improves over time?
A. Scientific data can be interpreted differently based on personal beliefs.
B. Scientific ideas change as new information is collected and interpreted.
C. Scientific theories are considered laws once they are proven by many scientists.
D. Scientific experiments can be repeated under different conditions with the same results
Scientific ideas change as new information is collected and interpreted
Scientists often make explanations about some aspect of the natural world when facts have been repeatedly confirmed through observations. Which of the following terms refers to these explanations?
A. inquiry B. theory C. hypothesis D. law
a theory
What 2 subatomic particles are located in the nucleus of an atom?
A. electron and neutron B. isotope C. electron cloud D. neutron and proton
Neutron and proton
Which element has 49 protons?
Indium (In)
What do elements in the same group have?
Similar properties
Consider the work of scientists investigating a popularly held theory. As scientists continue to investigate this particular theory, they begin to find evidence that contradicts one of the main ideas proposed by this theory. Although many previous researchers have supported the theory, the latest research definitely indicates one area of the theory is completely wrong. What should the researchers propose?
A. They should propose the need for a completely new theory based on the latest research.
B. They should propose disregarding the new results as they likely result from mistakes in the research. C. They should propose modifications to the existing theory that take into account their new discoveries. D. They should propose that different scientists conduct the same experiment to verify the original theory is wrong.
They should propose modifications to the existing theory that take into account their new discoveries
15. In Science class, Ganesh told his classmates that elements are like the letters of the alphabet. What did Ganesh mean by this analogy?
A. Each element has a name.
B. Each element is represented by one or two letters.
C. There are the same number of elements as there are letters in the alphabet.
D. There is a finite number of letters that can be combined in different ways to make many words
There is a finite number of letters that can be combined in different ways to make many words
Which subatomic particle is located in a cloud outside the nucleus?
Electron
The bar graph represents four elements and their relative atomic numbers. What would be the most likely positioning of these unknown elements in the periodic table?
W-X-Y-Z
Which element has chemical properties that are similar to oxygen meaning that it would react in the same way?
A. Sulfur B. Fluorine C. Phosphorus D. Neon
Sulfur
Scientific knowledge may change as new evidence or information is discovered. Which of the following would not be a result of new scientific research and information?
A. Binomial nomenclature is assigned to a recently identified plant species.
B. An endangered monkey species is put in a reserve for protection from extinction.
C. A newly discovered chemical element will be added to the periodic table of the elements.
D. A nonnative plant species will begin to reproduce rapidly after being introduced into a swamp ecosystem.
A nonnative plant species will begin to reproduce rapidly after being introduced into a swamp ecosystem.
Peter explores the periodic table and how atoms can combine to form compounds. He uses beads with different sizes and colors as models. Each different type of bead represents atoms from a different element. How can Peter best use the beads to show how compounds form in nature?
A. He can sort the beads by color and size, then join beads of the same color and size together.
B. He can arrange the beads into various formations using different colors and sizes multiple times.
C. He can pile all the beads together to show how all the atoms in nature join together to form one large mass.
D. He can glue 2 beads together to show that compounds only form from pairs of atoms.
He can arrange the beads into various formations using different colors and sizes multiple times
What is the center of an atom called?
Nucleus
This is what a sample of gold would be if it were reduced to the smallest possible particle of pure gold.
A. The sample would be reduced to atoms of gold. B. The sample would be reduced to molecules of gold.
C. The sample would be reduced to protons and neutrons of gold.
D. The sample would be reduced to electrons and protons of gold.
What are atoms of gold.
Mario discovered that sodium (Na) is found in Group 1, Period 3 on the periodic table. Where should Mario look for another element that has similar properties?
A. in Group 1
B. in Period 3
C. on the opposite side of the periodic table
D. for any other element that begins with the letter N
In Group 1
.In 1897, Joseph Thomson discovered that atoms contained electrons. He proposed a change in the atomic theory of that time, and the theory was modified because of his discovery. Since Thomson’s discovery, atomic theory has been further modified. What is the best explanation for why scientific theories are modified?
A. Theories more than five years old are out of date B. Scientists want to prove that the work of other scientists is wrong
C. New evidence that supports a revision prompts scientist to modify the earlier theories
D. So much information is available today that it is harder to focus research and disprove theories
New evidence that supports a revision prompts scientist to modify the earlier theories
The atomic theory explains that atoms are the smallest unit of an element and are composed of subatomic particles. Although we can not see atoms with our own eyes, scientific technology allows us the ability to explore these tiny building blocks of matter. Which of the following statements correctly describes the structure of an atom and its subatomic particles?
A. Atoms have a nucleus that contains electrons that are orbiting neutrons and protons that orbit the electrons
B. Atoms have a nucleus that contain electrons and neutrons; protons orbit around the nucleus
C. Atoms have a nucleus containing protons and neutrons; electrons surround the nucleus in a cloud D. Atoms consist of protons, neutrons, and electrons that all orbit each other in a large mass
Atoms have a nucleus containing protons and neutrons; electrons surround the nucleus in a cloud
What type of substance is always made up of a single type of atom?
A. Mixture B. Element C. Molecule D. Compound
Element
The human body contains a large variety of molecules, including carbohydrates, proteins, sugars, fats, and others. However, the human body is made mostly of three elements: carbon, hydrogen, and oxygen. Which statement best explains this apparent contradiction?
A. A small number of configurations have a large number of elements.
B. A small number of elements are arranged in a large number of configurations.
C. There are several elements in the human body that have not been discovered yet.
D. The human body does not need more than carbon, hydrogen, and oxygen to survive.
What are a small number of elements are arranged in a large number of configurations.
Based on the periodic table, which element would have properties most similar to those of phosphorus, (symbol P, atomic #15) and why?
A. sulfur, because both sulfur and phosphorus are solids
B. lithium, because lithium is in the top row of the periodic table
C. argon, because argon is at the end of the same row on the periodic table
D. nitrogen, because nitrogen is located right above phosphorus in the periodic table
nitrogen, because nitrogen is located right above phosphorus in the periodic table
Greek philosophers such as Democritus and Aristotle had ideas about the composition of matter. For example, Democritus believed matter was made of tiny, solid spheres that he called atomos, and Aristotle thought matter was made of earth, water, fire, and air. Aristotle's idea of matter was the accepted idea for over 2,000 years until John Dalton came up with a new theory about matter. Which of the following best explains why Dalton’s theory became more widely-accepted over Aristotle's theory?
A. Aristotle’s theory did not have enough direct evidence due to poor observational tools.
B. Dalton’s theory was more complete because more respected scientists found the ideas possible. C. Dalton’s theory had repeated observations which were supported by extensive evidence.
D. Aristotle’s theory became the law of conservation of mass when he documented phase changes of matter.
Dalton’s theory had repeated observations which were supported by extensive evidence.
When 2 or more different elements combine to form a molecule?
A. Element
B. Compound
C. Mixture
D. Atom
Compound