Ch. 4,5,6 Test
If E is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1- 20/10 E 2. 20/11 E 3. 21/9 E 4. 21/10 E
1 and 4
How many electrons does the ion Ca2+ contain?
18 electrons
In which of the following is the number of neutrons correctly represented?
238/92 U has 146 neutrons
How many electrons are in a rubidium ion (Rb+)?
36 electrons
How many protons, electrons, and neutrons does an atom with atomic number 50 and mass number 125 contain?
50 protons, 50 electrons, 75 neutrons
An element has an atomic number of 76. The number of protons and electrons in a neutral atom of the element are _________.
76 protons and 76 electrons
Using the periodic table, determine the number of neutrons in 16)
8
Which of the following sets of symbols represents isotopes of the same element?
84/38 M 86/38 M 87/38 M
Which element is in period 3 and is part of the halogen family?
Chlorine
Who was the man who lived from 460-370 BC and was among the first to suggest the idea of atoms?
Democritus
Who arranged the elements according to atomic mass and used the arrangement to predict the properties of missing elements?
Dmitri Mendeleev
Which model of the atom is thought to be true?
Electrons are distributed around the nucleus and occupy almost all the volume of the atom
In which of the following sets is the symbol of the element, the number of protons and the number of electrons given correctly?
In, 49 protons, 49 electrons
When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties. This is a statement of what law?
Law of Conservation of mass
Which of the following elements should be a good conductor of heat and electricity?
Potassium
Of the elements, Fe, Hg, U, and Te which is a representative element?
Te
Which element has an atomic number of 50?
Tin
Which of the following statements is true about ions?
When an anion forms, more electrons are transferred to it
What is the name for the Group 2a elements?
alkaline earth metals
What unit is used to measure weighted average atomic mass?
amu
The metals in group 1a,2a,3a
lose electrons when they form ions
The smallest particle of an element that retains the properties of that element is_____________
atom
The smallest particle of an element that retains the properties of the element
atom
the weighted average of the masses of the isotopes of an element
atomic mass
the units used to describe the mass of subatomic particle
atomic mass unit
the total number of protons in the nucleus of an atom
atomic number
Which of the following statements if true?
atoms of isotopes of an element have different numbers of neutrons
Which of the following elements is a transition metal?
copper
Emission of light from an atom occurs when an electron
drops from a higher to a lower energy level
a negatively charged subatomic particle
electron
Which group of elements is known as the alkali metals?
group 1a
Which groups is known as noble gases?
group 8a
How do the isotopes hydrogen-1 and hydrogen-2 differ?
hydrogen-2 has one neutron and the other has none
atoms with the same number of protons, but different numbers of neutrons
isotope
The sum of the protons and neutrons in an atom equals the __________
mass number
the total number of protons and neutrons in the nucleus of an atom
mass number
Isotopes of the same element have different
mass numbers
All atoms are
neutral, with the number of protons equaling the number of electrons
a subatomic particle with no charge
neutron
the central part of an atom, containing protons and neutrons
nucleus
The modern periodic table is arranged in order of increasing atomic______________
number
All atoms of the same element have the same ______________.
number of protons
Isotopes of the same element have different
numbers of neutrons
What are the horizontal rows on the periodic table called?
periods
What is the charge of a cation?
positive
a positively charged subatomic particle
proton
The atomic number of an element is the total number of which particles in the nucleus?
protons
The atomic number of element is the total number of which particles in the nucleus?
protons
The particle that are found in the nucleus of an atom are________
protons and neutrons
What does the number 84 in the name krypton-84 represent?
the mass number
Which of the following is true about subatomic particles?
the mass of a neutron nearly equals the mass of a proton
The atomic emission spectra of a sodium atom on Earth and of a sodium atom in the sun would be
the same
The mass number of an element is equal to _____________
the total number of protons and neutrons in the nucleus
The atomic mass of an element is the ________.
weighted average of the masses of the isotopes of the element