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FREE AND STUDY GAMES ABOUT SCIENCE TEST EXAM
QUESTIONS
Actual Qs and Ans Expert-Verified Explanation
This Exam contains:
-Guarantee passing score -70 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: Combination of chemical symbols and numbers that indicates which elements and how many atoms of each element are present in a molecule.
Answer:
Chemical formula Question 2: Explain why a stairway is a good model for the energy levels in an atom.
Answer:
Stairway is a good model because each energy level can be represented as a step is the lowest energy level and the electrons are close to the nucleus.Question 3: The chemical symbol for an element surrounded by as many dots as there are electrons in its outer energy level is called a ______.
Answer:
Electron dot diagram Question 4: A substance produced when elements combine and whose properties are different from each of the elements in it.
Answer:
Compound
Question 5: A ____ is a pure substance containing 2 or more elements that are chemically hooked.
Answer:
Compound Question 6: A helium atom has only two electrons. Why does helium behave as a Noble gas?
Answer:
The lowest energy level can contain only two electrons. Since this energy level is helium's outer level,it is full with two electrons.Question 7: Explain why groups 1 and 2 form many compounds with Groups 16 and 17.
Answer:
Elements in groups 1 and 2 lose one or two electrons easily. Elements in Groups 16 & 17 gain one or two electrons easily.Question 8: When two atoms share an electron unevenly and one of the atoms has as light negative charge as a result,their bond is referred to as a ______,
Answer:
Polar
Question 9: A pure substance that contains two or more elements.
Answer:
Compound Question 10: Molecules that do not have uneven charges are called ______ or bonds.
Answer:
Non-polar molecules
Question 11: Molecule that does not have two opposite ends or poles.
Answer:
Nonpolar Question 12: An atom that is no longer neutral because it has gained or lost an electron.
Answer:
Ion
Question 13: A ____ is the basic unit of a molecule compound. It is the neutral parted formed when atoms share electrons.
Answer:
Molecule Question 14: Explain how the arrangement of electrons in an atom is related to the periodic table.
Answer:
Elements that are all in the same period have the same energy levels. The group numbers tell you how many electrons are in the outer energy level. Period numbers tell you how many energy levels.Question 15: Which term describes the units that make up substances formed by ionic bonding?Ions , molecules , acids , atoms
Answer:
Ions
Question 16: Force that holds two atoms together.
Answer:
Chemical bond Question 17: An electron ____ is the chemical symbol for the element surrounded by as many dots as there electrons in its outer energy level.
Answer:
Dot diagram
Question 18: 1. Formed by gaining or losing electrons
- Ions are formed
- Basic units is the ions
- Metal + nonmetal
Answer:
Ionic
Question 19: When _______ occurs,electrons are either gained or lost. (Metal + nonmetal )
Answer:
Ionic bonding
Question 20: Columns in the periodic table are known as _______.
Answer:
Element families
Question 21: Which is NOT true about the molecule H_2_O?
It contains two hydrogen atoms , it contains one oxygen atom , it is a polar covalent bond , it is an ionic compound
Answer:
It contains one oxygen atom
Question 22: Metal + Metal
Formed when metals share pooled electrons.Bonding affects the properties of metals.
Answer:
Metallic
Question 23: An atoms _____ contains it's protons and neutrons.
Answer:
Nucleus Question 24: In the chemical formula CO_2,the subscript 2 shows which of the following?There are two oxygen ions , there are two oxygen atoms , there are two CO_2 molecules , there are two CO_2 compounds
Answer:
There are two oxygen atoms Question 25: The number of electrons in a neutral atom increase by one as you go from left to right across a _______ in the periodic table.
Answer:
Period
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