Chemistry Test RD

How many elements are on the periodic table?

118

Define electron.

A negatively charged subatomic particle.

Define neutron.

A neutral particle that is found in the nucleus of an atom.

What's the difference between accuracy and precision?

Accuracy- Describes the difference between the measurement and the part's actual value Precision-Describes the variation you see when you measure the same part repeatedly with the same device.

What is the first point of the atomic theory?

All matter is made of atoms, which are indivisible.

Define neutral atom.

An atom in which the number of protons is equal to the number of electrons.

Define ion.

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Define matter.

Anything that has mass and takes up space.

Who created the planetary model of the atom?

Bohr.

Which scientist Discovered radioactive particles?

Chadwick.

Define alchemy.

Combination of science magic and philosophy, which was practiced in medieval times.

Classify potassium fluoride as an element, compound, homogenous mixture, or a heterogeneous mixture.

Compound.

Which scientist thought atoms couldn't be divided?

Dalton.

What scientist created the periodic table?

Dmitri Mendeleev

Classify hydrogen as an element, compound, homogenous mixture, or a heterogeneous mixture.

Element.

What is the difference between exothermic and endothermic?

Exo- energy being released in the form of heat. endo- energy being absorbed.

Which phase of matter has the most energy?

Gas/plasma.

What are the columns on the periodic table called?

Groups/families.

What are the differences between homogenous and heterogenous mixtures? Give an example of each.

Heterogeneous- Able to be separated mixture; beef stew trail mix asphalt vomit ect. Homogenous- Unable to be separated mixture; gas, air, blood, ect.

Classify asphalt as an element, compound, homogenous mixture, or a heterogeneous mixture.

Heterogenous mixture.

Classify air as an element, compound, homogenous mixture, or a heterogeneous mixture.

Homogeneous mixture.

What are 7 diatomic elements?

Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, & iodine.

Draw and label a model of an atom.

Include proton, neutron, nucleus, electron, electron cloud, their charges, and the name of the model.

What happens to the speed of an object if you add or increase the energy of that object or the reaction involved?

It increases/speeds up.

Who created the Plum pudding model of the atom?

JJ Thomson.

Boiling point is the change of what to what?

Liquid to gas.

What's the law of conservation of matter?

Matter cannot be created or destroyed.

What type of elements have both metal and nonmetal properties?

Metalloids.

What are 2 atoms linked together called?

Molecule.

Isotopes have a different number of what subatomic particle?

Neutrons.

What is a subatomic particle?

Particles smaller than an atom. There's 4 types; protons, neutrons, electrons, and quarks.

What are the rows on the periodic table called?

Periods.

What is the difference between physical and chemical change? Give an example of each.

Physical- can be reversed. Chemical- can't be reversed.

What is the charge of the nucleus?

Positive charge.

Define proton.

Positively charged particle inside the nucleus.

What are the subatomic particles in the nucleus?

Protons and neutrons.

What's the difference between qualitative and quantitative data?

Qualitative- Descriptive Quantitative- Numerical

What is the 4th subatomic particle?

Quark.

Which scientist discovered the nucleus is positively charged?

Rutherford.

Which scientist discovered orbitals?

Schrodinger.

Sublimation is the change of what to what?

Solid to gas.

Melting point is the change of what to what?

Solid to liquid.

What are the 4 phases of matter?

Solid, liquid, gas, & plasma.

Which phase of matter has the least energy?

Solid.

Define atomic mass.

The average mass of all the isotopes of an element.

What component doesn't change in an experiment called?

The constant.

Which subatomic particle is the smallest?

The electron.

What side of the periodic table are metals on?

The left side.

Which subatomic particle is the largest?

The neutron.

What is the center of an atom called?

The nucleus.

What do the periods represent on the periodic table?

The number of electrons.

Define atomic number.

The number of protons in the nucleus of an atom.

What do the columns represent on the periodic table?

The number of valence electrons.

Name the 2 models of the atom.

The quantum & bohr models.

Define atom.

The smallest unit of matter.

Define Chemistry.

The study of matter and the changes it undergoes.

How is the atomic mass represented on the periodic table?

With decimals.

How is the atomic number represented on the periodic table?

With whole numbers.