Chem exam 1 pls help

D

A pure hypothetical substance, D, is found to change upon heating into two new pure substances: G and J. G

can be decomposed by chemical means and J cannot. From this we may conclude that:

(1) D is a compound, G and J are elements

(2) D, G, and J are all elements

(3) D, G, and J are all compounds

(4) D is a homogeneous mixture, G is a compound, J is an element

liquid

What is the physical state in which matter has a specific volume but does not have a specific shape?

Both homogenous and heterogeneous mixtures

For which of the following, can the composition vary?

(1) pure substance (2) element (3) homogeneous mixture (4) heterogeneous mixture (5) both homogeneous and heterogeneous mixtures

Chemical changes are the result of the combination, separation, and rearrangement of atoms

Dalton's atomic theory is based on several assumptions, which are listed below. Which of these assumptions still

hold(s) true today? I. All atoms of the same element are identical. II. Atoms are indivisible and unchangeable.

III) Chemical changes are the result of the combination, separation, and rearrangement of atoms.

Thomson’s cathode ray tube experiment

The discovery of the electron as a negatively charged particle within the atom was made using which

experiment?

electron

Which subatomic particle contributes the least to the mass of the atom?

cation, losing 3

The element aluminum will form a ______ by _________ electrons.

Composition

refers to the simple components that make up the material

Structures

refers to both the composition and arrangement of those simpler substances

Mixtures

contain more than one substance — and the substances are not bound in a fixed ratio

Alloys

mixtures of metals

color, temperature, mass, volume, shape, hardness, flexibility, conductivity

Examples of physical properties

Exothermic

A physical or chemical change that releases heat energy to the surroundings.

Endothermic

A physical or chemical change that absorbs energy from the surroundings.

theory

A model that explains and makes predictions about natural phenomena is referred to as a/an:

theory

an idea that is supported by evidence, or a paradigm for describing the world around us; describes how or why something happens

law

A statement that describes observations that are true in widely varying circumstances. Scientific laws often describe mathematical relationships. However, they do not explain why something occurs; they only observe that it occurs.

3

How many feet in a yard?

decimeter

One liter is equal to one cubic _____

d=m/v

Density formula

centimeter

1 ml equals 1 cubic

Antoine Lavoisier

observed that when a chemical change takes place, the total mass before and after the reaction is the same. Based on this research, he formulated the law of conservation of mass

lanthanide series/rare earth metals

First row of the inner transition elements

Actinide series

Second row of the inner transitions elements

Alessandro Volta

built the first battery (more formally called an electrochemical cell) — a device capable of moving electrically charged particles by placing alternating plates of zinc and copper on either side of pieces of cardboard soaked in sulfuric acid

J. J. Thomson

Discovered the electron

Rutherford

Discovered that most of the atom is empty space

photon

A small increment or packet of electromagnetic energy (often visible light).

Radio, micro, infrared, red visible, blue visble, uv, x, gamma

electromagnetic spectrum from lowest frequency to highest

c = wavelength*frequency

equation between speed, wavelength, and frequency

E=h*frequency

Energy of one photon using frequency

E=(h*c)/wavelength

Energy of one photon using wavelength

Line spectra

A pattern of light energies called blank; they are formed when gas-phase elements release energy. Each element has a characteristic one

Niels Bohr

proposed that electrons orbit the nucleus in much the same way that planets orbit the Sun

principal quantum number

What identifies the energy level

2n²

equation for how many electrons each energy level can hold

sphere

s sublevel shape

infinity

p sublevel shape

s and p

valence electrons occupy what sublevel(s)

highest

The valence electrons are only those in the ____ energy level

ions

atoms that gain or lose electrons

isoelectronic

Describes atoms or ions that have the same electron configuration.