About Atom & Matter

Question 1

signs of chemical change

Answer 1

Odor production
change in temperature (exothermic & endothermic)
change in color
formation of bubbles
formation of a precipitation

Question 2

depends on the amount of matter in the substance; length, mass, volume

Answer 2

extensive property

Question 3

depend only on the type of matter in the sample; density, melting point, hardness

Answer 3

intensive property

Question 4

temperature at which a liquid change into a solid

Answer 4

freezing point

Question 5

the temperature at which the liquid form of an element or compound is at equilibrium with the gaseous form

Answer 5

boiling point

Question 6

solid form of the element or compound is at equilibrium with the liquid form

Answer 6

melting point

Question 7

who coined the word atom? (which means that all matter is composed of very small particles)

Answer 7

Democritus

Question 8

able to formulate precise definition of the building blocks of matter (a.k.a atoms)

Answer 8

John Dalton

Question 9

atomic theory postulate #1

Answer 9

Elements are composed of extremely small particles called atoms

Question 10

atomic theory postulate #2

Answer 10

All atoms of a given element are identical both in mass and in chemical properties. However, the atoms of one element are different from the atoms of all other element

Question 11

atomic theory no. #3

Answer 11

atoms are not created nor destroyed in chemical reactions

Question 12

atomic theory no. #4

Answer 12

atoms combine in simple, fixed, whole-number ratios to form compounds

Question 13

law that states that samples of the same compounds always contain the same proportions by mass of the component elements

Answer 13

Law of definite proportion

Question 14

law that states that if two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element are in ratios of small whole numbers

Answer 14

law of multiple proportions

Question 15

law that states that there is no measurable changes in mass occurs during chemical reactions

Answer 15

law of conservation mass

Question 16

atoms that have the same number of protons, but different number of protons

Answer 16

isotopes

Question 17

periodic table: Law of Triads: group of 3 elements that exhibit similar properties

Answer 17

Johann Dobereiner

Question 18

periodic table: Law of octaves – every eight element had similar properties (not accepted and inaccurate)

Answer 18

John Newlands

Question 19

periodic table: 28 elements (listed by their valence)

Answer 19

Lothar Meyer

Question 20

Father of the periodic table; Prediction of the properties of several elements

Answer 20

Dmitri Mendeleev

Question 21

periodic table: Atomic number = number of protons

Answer 21

Henry Mosely

Question 22

certain patterns that describe specific aspects of the elements in the periodic table

Answer 22

periodic table

Question 23

distance from the center of nuclei to the surface of the neighboring atom; decreases from left to right (period); increases down to up

Answer 23

Atomic radius

Question 24

cation is smaller than the parent neutral atom; anion is larger than neutral atom

Answer 24

ionic radius

Question 25

amount of energy required to remove an electron
 Within a period – increases from left to right
 Within a group – decreases from top to bottom

Answer 25

ionization energy

Question 26

measure the ability of an atom to accept an electron

Answer 26

electron affinity

Question 27

ability of an atom in a chemical bond to attract chemical reaction

Answer 27

electronegativity