mass unit test

¡Supera tus tareas y exámenes ahora con Quizwiz!

How many protons are in an atom with an atomic number of 20, an atomic mass of 45, and a charge of +2?

20

If an atom has 10 protons, 10 neutrons, and 10 electrons, what is the mass of the atom?

20

What is the molar mass of sodium?

22.990

How many grams is 1.2 moles of Neon?

24 grams

How many neutrons are in an atom with an atomic number of 20, an atomic mass of 45, and a charge of +2?

25

The number 6.02 x 1023 is called...

Avogadro's number

an atom of nitrogen has 7 protons and 7 neutrons

ST

Atoms of different elements are exactly alike

always false

The smallest particle of an element that still retains all the properties of that element.

atom

Isotopes have a different what?

atomic mass

In Dalton's Atomic Theory, all elements consist of __________ that cannot be divided.

atoms

Which idea of Dalton's is no longer considered part of the modern view of atoms?

atoms of the same element have identical masses

Who is the scientist who proposed the "solar system" model of an atom where the electrons orbit around the nucleus?

bohr

One Atomic mass unit is defined as 1/12th the mass of one

carbon -12 atom

According to Dalton's Atomic Theory, ______________ (like water) are formed when two or more elements combine in a given ratio.

compounds

The law of conservation of mass states that mass cannot be

created or destroyed

Who is credited with developing the atomic theory? (Sometimes called the father of atomic theory)

dalton

The law of ___ proportions says that atoms combine in specific whole number ratios.

definite

The first person to ever talk about an atom was

democritus

J.J. Thomson used a cathode ray tube to find what particle in the atom?

electron

JJ Thompson's discoverd what?

electron

The cathode ray experiment proved the existence of which subatomic particle?

electron

Ernest Rutherford discovered that atoms were mostly _________________.

empty space

The nucleus is made up of protons and what other particle?

neutrons

What can you conclude from the fact that scientists continue to update the atomic model?

new information about atoms continue to be discovered

Nitrogen has three occurring isotopes: Nitrogen-13, Nitrogen-14, Nitrogen-15. Which isotope is the most abundant?

nitrogen-14

Rutherford's model of the atom introduced the _________.

nucleus

the gold foil experiment proved the existence of which subatomic particle?

nucleus

this contains most of the mass of an atom

nucleus

What is the atomic number?

number of protons

What is the mass number?

number of protons and neutrons

Bohr's planetary model involved the electrons residing in ____________.

orbitals

Where do you look to calculate the molar mass?

periodic table

Rutherford's experiment determined that the nucleus of an atom is tiny, dense and ______ charged.

positively

Isotopes all have the same number of ___________

protons

What subatomic particles would you find in the nucleus of an atom?

protons and neutrons

Which subatomic particles contribute the most to the mass of an atom?

protons and neutrons

Which has a greater mass: 1 mole of scandium or 2 moles of boron?

scandium

This model was developed after J.J. Thompson discovered electrons, a particle smaller than an atom. Is shows electrons floating freely in a positive space.

the "plum pudding model" of the atom

This model this model was the first to show a nucleus, consisting of protons and neutron. Electrons surround the nucleus but are not shown in distinct energy levels.

the "rutherford model" of an atom

This model added on to previous models by showing electrons existed at certain "energy levels". However is does not accurately show what those levels look like.

the "solar system model" of the atom

The Plum Pudding Model belongs to which scientist?

thomson

Protons and Electrons balance the charge of an atom.

true

James Chadwick discovered this particle.

neutron

What subatomic particle is electrically neutral (no charge)?

neutron

An element has two naturally occurring isotopes. One is 10.013 amu and is 19.9% abundant. The other is 11.01 amu and is 80.1% abundant. What is the average atomic mass? What element is it?

10.812, Boron

If an atom has 12 positively charged subatomic particles, which of the following must it also have to be considered a neutral atom?

12 electrons

What is the mass number and name of an element with 8 protons and 8 neutrons

16- oxygen

Which is the correct sequence of the scientists who made major changes in the model of the atom? 1-JJ Thomson 2-Erwin Schrodinger 3-John Dalton 4-Niels Bohr 5-Ernest Rutherford

3,1,5,4,2

The mass number of an element that has 18 protons, 18 electrons, and 19 neutrons is _____.

37

Lithium with atomic # 3 and mass number of 7 has how many neutrons?

4

How many moles are 2.85 x 1018 atoms of iron?

4.73 x 10-6 moles

Which conversion factor would you use to calculate correctly the mass of 2 moles of the element titanium?

47.87 g Ti / 1 mol Ti

How many atoms are in 8.5 mole of nickel?

5.1 * 1024 Ni atoms

How many atoms of iodine are in a mole of iodine?

6.02 x 1023

Carbon 14 has how many neutrons?

8

atoms of elements are electrically neutral

AT

relative atomic masses are measured in amus

AT

the charge on all protons is the same

AT

according to dalton's atomic theory, atoms are composed of protons, electrons, and neutrons

NT

the atomic number of an element is the sum of the protons and electron in the atom

NT

the atomic number of an element is the whole number that decreases as you read each row of the periodic table from left to right

NT

the mass of an electron is equal to the mass of a neutron

NT

Which statement best describes the locations of the subatomic particles?

The protons and neutrons are in the nucleus, while the electrons are in the cloud outside the nucleus

In chemistry, a "mole" is:

a large number used to count particles

What element contains 26 protons?

iron

Ag--110 and Ag--112 are two forms of silver with different mass # so they are

isotopes

The fact that matter is not created or destroyed in any chemical or physical change is called the _______.

law of conservation of mass

Which law supports the example that water is always make up of 2 g of hydrogen to 16 grams oxygen?

law of definite proportions

Which law would support the example of CO having 12 g C to 16 g oxygen and CO2 having 12 g C and 32 g oxygen

law of multiple proportions

In Dalton's Atomic Theory, atoms of a particular element have the same ___________.

mass

The law of ___ proportions states that atoms of the same types of elements can combine in different whole number ratios.

multiple

electrons have this type of charge?

negative

An atom's overall charge is ________.

neutral


Conjuntos de estudio relacionados

7.3.16 Practice Questions Test Out

View Set

Chapter 53: Assessment of Kidney and Urinary Function

View Set

Sociology Chapter 10 Test Review

View Set

Urinary System Career Specialties

View Set

Verbs ending in -gar, -car and -zar in the preterite yo form.

View Set