The Nucleus of an Atom

Subatomic particle with positive charge

proton

The mass number of an atom is equal to the total number of its

protons and neutrons

What are the two subatomic particles found in the nucleus?

protons and neutrons

The atomic number of an atom is always equal to the number of

protons in the nucleus

An atom of carbon-14 contains ____ protons, ____ neutrons, and ____ electrons

6, 8, 6

A neutral oxygen atom differs from an ion of oxygen (O2-) because the atom has

fewer electrons

Charged particle formed when an atom gains or loses electrons.

ion

Atom of an element that has the same number of protons as another atom of the same element, but a different number of neutrons.

isotope

Sum of the protons and neutrons in the nucleus of an atom.

mass number

The subatomic particles 14 6C and 14 7N are similar in that they both have the same

mass number

Experimental evidence indicates that the nucleus of an atom contains...

most of the mass of an atom

Subatomic particle with no electric charge

neutron

Which particle is electrically neutral?

neutron

The small, dense, positively charged center of an atom

nucleus

The total number of electrons in a neutral atom of every element is always equal to the atom's

number of protons

Two atoms will always have the same atomic number if they have the same

number of protons

The nucleus of an atom of 127I contains ____ protons and ____ neutrons

53, 74

The number of protons in an atom of hydrogen is

1

What are two discoveries from Rutherford's gold foil experiment

1. most of the alpha particles went through Au foil UNDEFLECTED, most of the atoms volume is simply a vacuum 2. the alpha particles that were deflected made a distinct and repetitive pattern, the nucleus is positive, dense center of an atom

What is the total number of neutrons in an atom of 19F?

10

What is the total number of electrons in a Mg atom?

12

The Al3+ ion has____ protons, ____ neutrons and ____ electrons

13, 14, 10

In which pair does each atom have the same number of neutrons?

15N and 16O

What is the total number of protons in an atom of 36Cl?

17

Which pair of atoms are isotopes of element x?

226 91X and 227 91X

How many electrons are in a neutral atom of 7 3Li?

3

What is the mass number of a 3 1H atom?

3

A sample of element X contains 90% of 35X atoms, 8% of 37X atoms, and 2% of 38X atoms. Calculate the average atomic mass.

35.22 amu

Draw an atomic model to represent Be2+

4 protons, 5 neutrons, 2 electrons

Draw an atomic model to represent 9Be

4 protons, 5 neutrons, 4 electrons

What is the mass number of an ion that consists of 20 protons, 20 neutrons, and 18 electrons?

40

Which pair of elements are isotopes?

40 19K and 42 19K

What is the symbol for an atom containing 20 protons and 22 neutrons?

Ca

If the nucleus of an atom is represented as 11X, the atom is

Na (sodium)

Compared to the charge and mass of a proton, an electron has

an opposite charge and a smaller mass

the smallest particle of an element that retains the properties of that element

atom

Weighted average of the masses of all the naturally occurring isotopes of an element.

atomic mass

All atoms of a given element must have the same

atomic number

Number of protons in the nucleus of an atom

atomic number

An isotope of which element has an atomic number of 6 and a mass number of 14?

carbon

The nucleus is the part of the atom that

contains most of the atom's total mass

Subatomic particle with negative charge

electron

Simplest type of a pure substance.

element

As a Na atom forms Na+ ion, the number of protons in its nucleus...

remains the same

How to tell is atoms are an isotope of an element

same number on bottom, different number on top