Science EOC 9th grade

Ionic bonds

1) metal + nonmetal 2) transfers electrons 3) stronger bonds 4) high boiling points

Covalent bonds

1) nonmetal + nonmetal 2) shares electrons 3) low melting and boiling points

If an atom of sodium combines with (captures) an alpha particle that has 2 protons and 2 neutrons, its new mass number will be

27 amu because the sodium nucleus contains 23 protons and neutrons and 4 more are added from the alpha particle.

A carbon-12 atom has 6 protons, 6 neutrons, and 6 electrons. How many protons does a carbon-14 atom have?

6. All isotopes of any element have the same number of protons.

neutral pH level

7

Single Replacement

A + BC --> B + AC

An electric current is created in a long thin wire. How will increasing the current and changing the direction of the current effect the direction that a compass placed under the wire will point?

A compass can show that an magnetic field is present. If we change the direction of the current, the compass will flip exactly 180 degrees.

electrolyte

A compound that conducts an electric current in aqueous solution or in the molten state.

solid

A form of matter that has a definite shape and volume

concentration

A measurement of how much solute exists within a certain volume of solvent

anion

A negatively charged ion

cation

A positively charged ion

vacuum

A space where no particles of matter exist

liquid

A state of matter that has no definite shape but has a definite volume.

gas

A state of matter with no definite shape or volume

Double replacement

AB + CD = AD + CB

group 1

Alkali Metals (very reactive)

Student Example Jane Electric blanket Emily Refrigerator John Flashlight Michelle Table lamp Mr. Cortez asked his students to give examples in which electrical energy is transformed into heat. Students worked in a small group. They recorded their answers in a table. If you were Mr. Cortez, how would you comment on the answers in the table?

All the students are correct. Whenever an appliance or a light uses electricity, it gives off heat energy also. That may not be the purpose of the appliance, but heat is a by-product anyway.

Why do you hear a ambulance louder as it gets closer to you

As the ambulance got closer, the siren's pitch got higher because the sound waves were pushed closer together. The shorter the wavelength, the higher the frequency and the higher the pitch.

Why does the sound of something moving away from you seem to change to a lower and lower pitch?

As the source moves away, the sound waves stretches out relative to the person standing still; so the pitch drops.

Solution What it is made of A Water and Salt B Water and Sugar C Water and HCl D Water and NaOH

B because when they form a solution, the charged ions allow for the flow of electricity. Sugar is a covalent compound. When in solution, it does not form ions, thus it will not allow for electricity to flow.

refraction

Bending of light

Alternating Current or AC is better for use in ___________, while DC direct current is needed in _________ .

electric power transmisson, electronics. AC allows the use of transformers and electronics involving computer chip require DC.

group 13

Boron Family

If we compare and contrast electromagnetic waves with sound waves, all BUT one statement is true. That is

electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere.

Name a liquid nonmetal

Bromine

What is the difference between electromagnetic waves and sound waves?

electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere.

groups 14

Carbon Family

Listed below are sets of elements. Which group contains elements that have the following characteristics: 1) At least one is a metalloid. 2) At least one forms an ion with a charge of -2. 3) At least one is a gas. 4) At least one is a halogen.

Chlorine, sulfur, and silicon

Current that moves in one direction from negative to positive. May be created by a battery. Is generally NOT found in U.S. electrical outlets. Which type of current is described by these statements?

DC

If you want to conduct an electrical current, which situation would produce a solution capable of this?

Dissolving solid NaF in water.Dissolving sugar in water will not since sugar just dissolves but not into ions. Oil is nonpolar so water nor NaBr will dissolve in it.

A train whistle is at a higher pitch (note) as it approaches you and then drops to a lower pitch as it moves away. This effect is called

Doppler Effect

Electrical energy can be transformed into other types of energy. We often experience this transformation of energy in our everyday lives. In one example the intended energy transformation produces thermal energy. That is the answer choices a) a car b) a television c) a flashlight d) a crock pot

Electrical energy is transformed into thermal energy in the electric crock pot. Electrical energy enters the crock pot by traveling through the outlet and power cord. The crock pot then converts the energy to generate thermal energy.

True/False Electromagnetic radiation travels in the form of longitudinal waves.

Electromagnetic radiation DOES NOT travels in the form of longitudinal waves. It travels in the form of transverse waves and travel through a vacuum

All BUT one statement applies to electromagnetic radiation. That is

Electromagnetic radiation travels in the form of longitudinal waves.

True/False X-ray travels faster through solids than gases

False. X-rays travel faster through gases than solids

What are the 2 most reactive groups on the periodic table? Explain.

Group 1 and Group 17. Group 1 loses 1 electron and group 17 needs 1 electron

Which group is very unreactive on the periodic table? Explain.

Group 18/Noble gases. They have complete outer energy levels

group 17

Halogens

What are the gases on the periodic table?

Hydrogen, Nitrogen, Oxygen, Fluorine and all of group 18

why is an ionic solution is a good conductor of electricity while a covalent solution is a poor conductor?

Ionic compounds form charged particles in solution, and electricity will only flow if charged particles are present.

What can we say about the rock as it falls to Earth?

It accelerates as it falls.

fusion

Joins 2 lighter atoms into a larger one.

Has luster Malleable Ductile Conductor Solid at room temperature Which element could be described by the list of properties above?

Magnesium because it describes a metal and mercury is a liquid at room temperature even though it is a metal

Name a liquid metal

Mercury

What would occur if you were to replace the bulb in the circuit with a much brighter bulb?

More energy would be transferred from electrical to light. the brighter bulb would require more energy, and since it is available in this system, would use the energy to create a brighter light.

group 15

Nitrogen Family

Covalent solutes are considered non-electrolytes. What does this mean for the conductivity of the solution?

Non-electrolytes dissolve and do not dissociate in water providing no charged ions to conduct electricity.

Which of these reactions is responsible for high amounts of energy radiating from stars, including the Sun?

Nuclear fusion

group 16

Oxygen Family

How is the pressure of a gas related to its concentration of particles?

Pressure will compress a gas, reducing its volume and giving it a greater density and concentration of particles.

Mechanical (sound) waves are unable to travel through a vacuum, such as through space, but radio waves are transmitted to Earth from satellites. How is this possible?

Radio waves are electromagnetic waves.

The alkali metals all react vigorously with water. Which alkali metal would react to the greatest extent if you have equal amounts of each?

Rb because the chemical reactivity of an element increases as you go down a group.

Where are most of the gases located on periodic table?

Right side

Sound waves require a medium to travel through, such as a solid, liquid or gas because

Sound is molecules bumping into one another. They can't bump without a medium, however.

Which waves move by replacing one particle with another?

Sound waves

Which wave CANNOT travel through the vacuum of space?

Sound waves can not travel through the vacuum of space. Sound needs particles to transmit its energy through. Space is a vacuum, with no particles in it.

conductivity

The ability or power to transmit heat, electricity, or sound.

What would be the result of an alpha particle coming into a magnetic field?

The alpha particle will be deflected in a curve path.

Elaborate on the reason why heating water up will increase the rate of dissolving for a solute.

The average kinetic energy of the molecules that make up the solution also increases with increasing temperature. This increase in kinetic energy allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions.

What is an important trend you would notice about the elements as you move from left to right?

The elements change from metals to nonmetals

Gravity is a force between any two objects with mass. Why doesn't a person feel a gravitational force between him/herself and another person?

The gravitational forces of people is so small it is overshadowed by that of Earth.

Sonar signals and infrared light are are used to send messages to submarines deep under water. If we compare the two signals, which one will send the messages the fastest?

The infrared light gets there faster and is clearer.Light waves travel much faster than mechanical waves and are more likely to remain constant during travel

When a person does work on an object, the object gains energy. As a bicycle rider rides from the bottom to the top of a hill, the energy from the work can become which combination of types of energy.

The riders work becomes a combination of gravitational potential, kinetic energy and heat The rider probably speeds up, climbs to a higher position and there is friction involved.

Which is an example of nuclear energy being converted into heat and light energy?

The sun gets its heat and light energy from the fusion of hydrogen nuclei at its core. The other example all come from chemical energy - which deals with the electrons, and not the nucleus, of atoms.

An inclined plane is made out of a short plank of wood. It is used to move a 300N box up onto a tabletop 1m above the floor. What would happen to the work and mechanical advantage if a longer plank were used to accomplish the same task?

The work would remain the same and mechanical advantage would increase.

All the elements of a family in the periodic table have what feature in common?

They all have similar chemical properties.

AM Radio Waves Ultraviolet Light X Rays Visible Light What is true for ALL of the examples of electromagnetic waves?

They all move at the same speed in a vacuum.

A nuclear power plant, a hydroelectric dam, a coal burning power plant have what in common?

They are all sources of electricity.

How are electromagnetic waves produced?

They are produced when an electric charge vibrates or accelerates

Elements in the same group/family of the periodic table are similar in what way?

They have the same number of valence electrons.

True/False Electromagnetic waves move faster than electromagnetic waves

True

True/False Electromagnetic waves travel faster than mechanical waves through the space and atmosphere.

True

True/False In matter, molecules never stop moving.

True

True/False Mechanical waves tend to have longer wavelengths then electromagnetic waves

True

groups/families

Vertical columns on the periodic table

Most electrical power generation (except for solar) converts motion into electricity using a generator. The two required components for a generator are

a coil of wire and a magnet in relative motion to induce an electric current.

plasma state

a gaseous system composed of positively-charged particles and negatively-charged electrons

decomposition reaction

a reaction in which a single compound breaks down to form two or more simpler substances

synthesis reaction

a reaction in which two or more substances combine to form a new compound

aqueous solution

a solution in which water is the solvent

Boiling point

a temperature where the vapor pressure of a liquid equals the atmospheric pressure.

group 2

alkaline earth metals (reactive but not as group 1)

Where are metalloids located on the periodic table?

along the staircase

radioactive element

an unstable element that breaks down into a different element

The Doppler effect is a change in the ________________ frequency of sound caused by the motion of either their listener or the sound source.

apparent

Sodium ions are used by your body every time you move a muscle. The difference between the Na+ ions and atomic Na is that

atomic sodium has one more electron. The ions of an element have an unmatched number of protons and electrons.

Elements are arranged in groups by similar atomic structure on the periodic table. This allows for an element's properties to be predicted based on general periodic trends. One of these trends, electronegativity, increases up a group and to the right along a period and can be defined as the atom's ability to _______.

attract a bonding pair of electrons toward itself.

Why can television satellites, which broadcast information as electromagnetic radiation, send signals from the vacuum of space?

because electromagnetic radiation does not need a medium to travel through.

Why do electromagnetic waves not require a medium for travel?

because electromagnetic waves transmit energy without compressing the particles of the medium

Why does alternating current change direction 50 to 60 times per second?

because it is produced by a generator that changes current direction as it spins

This radioactive particle, emitted from carbon-14, has a negative charge. It contains sufficient energy to burn human skin and can pass through paper. It is a(n) ___________ particle.

beta particle

Plasma particles have

charged particles inside

diatomic

consisting of two atoms

Direct current, DC, flows in a _________ direction while alternating current, AC, the direction of flow ___________.

constant, periodically reverses

Almost all ionic compounds are ____________________ at room temperature.

crystalline solids

Light waves

do not require a medium

Elements are arranged in groups by similar atomic structure on the periodic table. This allows for an element's properties to be predicted based on general periodic trends. One of these trends, electron affinity, increases up a group and to the right along a period and can be defined as the ______________.

energy required to add an electron

MgX2 Very low density Highly reactive Diatomic Using the periodic table, determine which element these characteristics MOST LIKELY describe.

fluorine because it is a gas at room temperature and gases tend to have a low density

Heating gas to create plasma can yield

free electrons

Nuclear _________ reactions convert protons into helium; thus, becoming the source of all energy radiated by the sun.

fusion

Which form of radiation is used to directly INCREASE the temperature of water in a nuclear reactor?

gamma radiation

Identify the correct order of increasing intermolecular force of attraction for the three most common states of matter.

gas → liquid → solid

neon, chlorine, and hydrogen are __________ at room temperature

gases

Which is a source of AC current?

generator

Base pH level

greater than 7

Before the fission process takes place, lead-207 is bombarded with neutrons, it can change into

lead-208, because Acquiring neutrons does not change the identity of the atom. In this case, lead-207 will change to lead-208. The only way to change the identity of the element is for the protons to change. Lead-206 is impossible since we are adding neutrons, not subtracting them.

Where are metals located on the periodic table?

left of staircase

Acid pH level

less than 7

Sound waves are mechanical waves in which the particles in the medium vibrate in a direction parallel to the direction of energy transport. Identify another name for this type of wave motion.

longitudinal waves

The amount of gravitational force exerted on each other between two objects depends on their

mass and distance.

medium

matter through which a wave travels

Transverse waves

mechanical waves in which the particles in the medium vibrate in a direction perpendicular to the direction of energy transport.

How many elements are solids on the periodic table?

mostly

As an atom's nucleus gets larger the electric charges repelling the protons get larger. To compensate for this greater electric charge the atom

needs fewer electrons to gain enough nuclear binding forces to overcome the repulsion.

group 18

noble gases

inside stars matter to energy high temperatures strong gravitational attraction The conditions listed above would be just right for all BUT one of the following to occur. That would be

nuclear fission.

Elements are arranged in groups by similar atomic structure on the periodic table. This allows for an element's properties to be predicted based on general periodic trends. One of these trends, atomic radius, increases down a group and to the left along a period and can be defined as __________.

one-half the distance between the nuclei of two atoms

mechanical advantage

output force/input force

A police car is parked by the side of a highway and its siren emits a sound measuring 750 Hz. As you approach the police car from a distance, you hear a change in the sound. The change is in the sound's

pitch and frequency

The nucleus of any atom requires a strong force to hold it together. This strong force is required because

positive protons in the nucleus repel each other.

physical property

property of matter that can be identified without changing the identity of the substance.

Which type of wave can be transmitted through the vacuum of space

radio waves

Similarities between Compression/sound waves and transverse/ electromagnetic waves

reflection, refraction, transfers energy

Where are nonmetals located on the periodic table?

right of staircase

There is a single path for electrons. The current decreases when additional resistors are added. The current will be the same in each resistor. These statements BEST describe a(n) _____________ circuit.

series

Potassium is a __________ at room temperature

solid

Some elements have a low degree of freedom and high intermolecular forces between its molecules. These elements are ________ at room temperature.

solid

fission

splits a larger atom into 2 or smaller ones

What statement is not true when two neutrons are added to oxygen-16?

the charge of the oxygen atom changes

A major difference between AC and DC electricity is that

the current in AC electricity varies in magnitude and direction. DC is supplied by a battery

One of the negative aspects of using nuclear power as an alternative energy source is

the disposal of byproducts

In nuclear fission and fusion the mass defect is

the mass lost during the reaction that is converted into energy.

Gravity on the moon is about 1/6th the gravity felt on the earth. This is because

the moon is much less massive than the earth.

melting point

the temperature at which a solid becomes liquid.

Two people each hold the end of a rope and create waves by moving their arms up and down. This wave is best classified as a transverse wave because

the wave is moving horizontally as the particles of the rope move up and down.In a transverse wave, the vibrations of the particles are always perpendicular to the direction of the wave's motion.

Pushing down on a piston causes an increase in pressure and a decrease in the volume of the gas in the cylinder. This is BEST explained by the fact that

there is a large relative distance between gas molecules.

Sound waves cannot travel in a vacuum because

there is no medium for the sound waves to travel through.

Group 3-12

transition metals

Waves in water are mechanical waves in which the particles in the medium move in a direction perpendicular to the direction of energy transport. Identify another name for this type of wave motion.

transverse waves. the particles in the medium vibrate in a direction perpendicular to the direction of energy transport.

In a _____________ wave, vibrations are perpendicular to the direction of the wave motion. In a _____________ wave, vibrations are parallel to the direction of the wave motion.

transverse, longitudinal

Compression or sound waves behave a lot like transverse or electromagnetic waves. Compression waves exhibit ALL BUT one of the following behaviors. That is

travel through a vacuum

Compression or sound waves behave a lot like transverse or electromagnetic waves. Compression waves exhibit ALL BUT one of the following behaviors. That is

travel through a vacuum.

unstable isotope

undergoes spontaneous nuclear decay and is referred to as a radioisotope.