Chem isotopes Test
Elements that boarder the staircase are
Classified as Metalloids
The smallest and lightest subatomic particle is the
Electron
In a neutral atom, the number of protons in the nucleus is balanced by an equal number of
Electrons
representative element families: (Group is column) Group 1 - Group 2 - Group 3-12 - Group 17 - Group 18 -
Group 1-Alkali metals Group 2 - Alkaline Earth Metals Group 3-12 - Transition metals Group 17 - halogens (halides) Group 18 - Nobel Gases
Columns (vertical) are the ______ also known as ______
Groups Families
Helium has an average mass of 4.0026. Which of these isotopes is the most common?
He-4
How do the isotopes hydrogen-1 and hydrogen-2 differ?
Hydrogen-1 has one neutron And Hydrogen-2 has none
78 36 KR This isotope is called and has how many neutrons?
Krypton-78 42 neutrons
In a hyphenated symbol (fluorine-19) the 19 is the:
Mass number
The mass of a neutron nearly equals the
Mass of a proton
What is the first step in calculating the average atomic mass of isotopes?
Multiply the masses by the percentages
Which isotope has 11 protons and 12 neutrons
Na-23
Strontium-90 has how many neutrons?
52
Given the mass number is 14 and the number of protons is 6, find the number of neutrons
8
9 4 Be the mass number of this isotope is
9
Strontium-90 has a mass number of?
90
Arsenic has an average mass of 74.992. Which of these isotopes of the most common?
As-75
Isotopes of one element have the same
Atomic number
Which isotope has 14 protons and 15 neutrons?
Si-29
Magnesium- 25 has __ protons and __ neutrons
12 13
How many protons does 28 13 AL have?
13
What is the atomic mass of an oxygen isotope, which has 8 neutrons
16
62 Ni The atomic number of this isotope is: This isotope is called:
28 Nickel-62
Given the mass number is 63 and the number of protons is 29, find the number of neutrons
34
Strontium-90 has an atomic number of
38
Given the number of electrons is 42, find the number of protons given the mass number is 96
42
75 33 M. This isotope has how many neutrons? This isotope is called:
42 As
Isotopes have different numbers of
Neutrons
Isotopes vary in their number of
Neutrons
atoms of the same element that have different numbers of _____ are called _____
Neutrons Isotopes
The stair case separates metals from
Non metal elements
Isotopes have the same number of___
Protons
The atomic number is the number of
Protons
What subatomic particle determines the identity of an element?
Protons
color of the element symbols represent their state of matter at room temperature: Red - Blue - Black -
Red - gas Blue - liquid Black - solid
"Periods" are the
Rows
T/F all isotopes of an element have the same atomic number?
True
