Chemistry D425 2025 update|comprehensive questions and verified
Chemistry D425
answers (complete solutions) Exam|GRADE A+!!
Study online at https://quizlet.com/_d0yw5a
1. How is matter classified? pure substances and mix-
tures
2. Avogadro's number number of representative
particles in a mole, 6.02 X
10^23
3. Words like atom, particles, molecules, formula units use Avogadro's number
mean? 6.02x10^23
4. Imperial System the system of measurement
used in the United States
5. What is an element? A substance that cannot be
broken down into simpler
substances
6. What is an compound? pure substance that contains
more than one element and
can be broken down into
chemically simpler compo-
nents
7. What is a mixture? is a physical blend of two
or more pure substances
where each retains its own
identity and properties in
the mixture
8. What are the three phases of matter? solid, liquid, gas
9. What is matter composed of? atoms
10. How is energy transferred? heat and work
, Chemistry D425
Study online at https://quizlet.com/_d0yw5a
11. What is the motion of energy? kinetic energy
12. what is resting energy? potential energy
13. What is a molecule ? a group of two or more
atoms held together by
chemical bonds
14. Is matter affected by physical changes? physical changes DO NOT al-
ter the composition of mat-
ter
15. Is matter affected by chemical changes ? Chemical changes transform
matter in such a way that
the identity or chemical sub-
stance changes
16. matter can neither be created nor destroyed What is the law of conserva-
tion of mass?
17. bonding electron pair two electrons shared be-
tween atoms
18. What are core electrons? inner electrons core shell
19. What are colvalent bonds? bond formed by the sharing
of electrons between non-
metals
example: H2O, NH3
20. valance electrons electrons in the outermost
shell
Chemistry D425
answers (complete solutions) Exam|GRADE A+!!
Study online at https://quizlet.com/_d0yw5a
1. How is matter classified? pure substances and mix-
tures
2. Avogadro's number number of representative
particles in a mole, 6.02 X
10^23
3. Words like atom, particles, molecules, formula units use Avogadro's number
mean? 6.02x10^23
4. Imperial System the system of measurement
used in the United States
5. What is an element? A substance that cannot be
broken down into simpler
substances
6. What is an compound? pure substance that contains
more than one element and
can be broken down into
chemically simpler compo-
nents
7. What is a mixture? is a physical blend of two
or more pure substances
where each retains its own
identity and properties in
the mixture
8. What are the three phases of matter? solid, liquid, gas
9. What is matter composed of? atoms
10. How is energy transferred? heat and work
, Chemistry D425
Study online at https://quizlet.com/_d0yw5a
11. What is the motion of energy? kinetic energy
12. what is resting energy? potential energy
13. What is a molecule ? a group of two or more
atoms held together by
chemical bonds
14. Is matter affected by physical changes? physical changes DO NOT al-
ter the composition of mat-
ter
15. Is matter affected by chemical changes ? Chemical changes transform
matter in such a way that
the identity or chemical sub-
stance changes
16. matter can neither be created nor destroyed What is the law of conserva-
tion of mass?
17. bonding electron pair two electrons shared be-
tween atoms
18. What are core electrons? inner electrons core shell
19. What are colvalent bonds? bond formed by the sharing
of electrons between non-
metals
example: H2O, NH3
20. valance electrons electrons in the outermost
shell
