Science Chapter 3

Atoms are made of made of smaller particles called…

protons, neutrons, and electrons

nucleus

very small center core of an atom

electrons surround …

the nucleus

The group of protons and neutrons are in the…

nucleus

Protons have a …

positive charge

neutrons have …

no charge

electrons

move rapidly around the nucleus and have a negative electric charge

an electron is shown as the symbol

e^—

if there are 6 protons there are x amount of electrons

6 electrons

the positive charge of protons equals the the negative charge of electrons which causes a

balence

electrons with higher energy move farther from the …

nucleus

what occupies most of an atom’s volume

electrons

electrons have a much lower mass than…

protons

what two things are close in mass

a proton and a neutron

atomic mass units abreviation

amu

a proton or neutron has an equal mass to about one…

amu

an element can be identified by the number of____ in the nucleus of its atoms

protons

Every atom of an element has the same number of

protons

each element has a unique…

atomic number

an element can be identified by the number of protons in the nucleus of its atoms

true

atoms with the same number of protons and a different number of neutrons are called…

isotopes

an isotope is identified by its…

mass number

mass number

the sum of the protons and neutrons in the nucleus of an atom

because atoms are so small, scientists create models to describe them

true

model

may be a diagram, a mental picture, a mathematical statement, or an object that helps explain ideas about the natural world

models can be used to…

crash test dummies, safety designs

What are the three main particles in an atom?

atoms are made of protons, neutrons, and electrons

why do atoms have no electric charge even though most of their particles have charges?

Atoms do not have an electric charge because the number of protons and electrons are the same. When they are the same they cancel each other out allowing for a balance. 

How can atomic numbers be used to distinguish one element from another?

The atomic number of an element is the number of protons in its nucleus. 

What is the main reason that scientists use models to study atoms?

Scientists use models to study atoms because the atoms are so small. They also use the models to help describe atoms.

What kind of information do scientists seek when using models to study atoms?

Models are used to study objects and events that are too small, too large, too slow, too fast, too dangerous, or too far away to see. Models can also help make and test predictions. 

In what order did Mendeleev arrange the elements in the first periodic table?

Mendeleev created a periodic table that arranged the elements by increasing order of atomic mass.

What pattern did Mendeleev discover when he arranged the elements?

Mendeleev discovered that the properties of the elements repeated. The way that the elements reacted with water the same way. So if lithium and potassium have the same reaction to water they would be placed in the same group. 

Describe the two differences between Mendeleev’s periodic table and the modern periodic table.

In Mendeleev’s periodic table the elements are listed vertically rather than in the current table the same elements are in a chart and are placed horizontally. The modern periodic table was arranged by atomic number rather than atomic mass. 

List three kinds of information about an element that can be found in a square of the periodic table.

The three kinds of information that an element will have on the periodic table are atomic number, chemical symbol or name, and the atomic mass.

Why aren’t the atomic masses of most elements whole numbers?

The atomic masses of most elements are not whole numbers because most elements consist of a mixture of isotopes and they find the average.

What does an element’s location in the periodic table tell you about that element?

An element’s location tells you the properties of the elements.

What properties of metals do the terms conductivity and ductility describe?

Conductivity is when an object is able to transfer heat or electricity to another object. A ductile material is one that is able to be pulled out or drawn into a wire.

 Give an example of how the ductility of metal can be useful.

Ductility would be useful for creating electric wires because it would have the ability to stretch out into a wire.

What property of metals led to the use of plastic or wood handles on many metal cooking utensils? Explain

You should use plastic or wood handles because the conductivity of the metal would burn you when holding it.

What family of elements in the periodic table contains the most reactive metals?

The family of alkali metals contains the most reactive metals. When alkali metals react with other elements they will lose one electron.

What area of the periodic table is the best place to look for a metal that could be used to coat another metal to protect it from corrosion?

The best place to look for a metal that could be used to coat another metal would be closer to the right side of the periodic table.

Describe the general process by which new elements are synthesized.

When the two nuclei hit each other at very high speeds the nuclei would combine creating one element.

How is plutonium created

Plutonium is created by crashing the nuclei of uranium with neutrons in a nuclear reactor.

What physical and chemical properties are found among nonmetals?

The physical properties of nonmetals are mostly the opposite of metals. Solid nonmetals are not shiny, brittle, not malleable, and not ductile. Nonmetals usually will have lower densities than metals. Nonmetals are also poor conductors of heat and electricity.

The chemical properties of nonmetals are that most nonmetals are reactive so they easily form compounds. 

 What happens to the atoms of most nonmetals when they react with other elements?

Atoms of nonmetals usually will gain or share electrons when they react with other atoms.

How do the physical and chemical properties of the halogens compare with those of the noble gases?

Halogens are highly reactive versus noble gases are not reactive usually. Halogens form compounds that are very useful while noble gases do not form compounds.

Noble gases are neon unlike halogens.

Where in the periodic table are the metalloids found?

In the periodic table the metalloids are found in groups 13 to 16.

What are three uses of metalloids?

Cleaning materials, semiconductors, and sand can be used in metalloids.

What property makes certain metalloids useful as “switches” to turn a small electric current on and off?

Semiconductors allow for certain metalloids to be useful as “switches” to turn a small electric current on and off.

What is the process that produces elementss in stars?

The process in which stars produce elements is called nuclear fusion. A nuclear fusion is when “stars on a huge scale, combines smaller nuclei into larger nuclei, creating heavier elements”(109).

How are the elements carbon,nitrogen, and oxygen produced in stars like the sun?

When a nuclear fusion occurs the fusion creates new elements in the stars. Carbon, nitrogen, and oxygen are formed through nuclear fusion. The product of fusions creates new fusions which create new elements.

Why can elements be produced in the sun but not in eatrh’s atmosphere?

In the sun it is very hot and has high pressure. Inside of the sun and other stars it is very compact, this allows for the fusion of nuclei. On Earth the atmosphere is not compact so fusions will not occur for new elements to be formed.

what is a supernova?

A supernova is when a massive star explodes.

What conditon of a supernova cause elements that are heavier than iron to form?

 A supernova produces a lot of energy for a new nuclear fusion reaction that can create elements heavier than iron.