Atoms
Are two atoms of the same element identical?
Not always.
What is a compound?
A pure chemical substance made of two or more different elements chemically bonded together in a fixed ratio.
Define an element
Pure substance with only one type of atom
what ice an chemical Symbol
A one-or two-letter code for an elements that is used by scientist in all countries
Define the meaning of an atom.
The smallest part of an element that can exist.
Why are atoms electrically neutral?
Equal number of protons and electrons
What type of bond is in NaCl?
Ionic bond
which group of elements is the least reactive?
Noble gases
What is the symbol for sodium?
Na
Define the meaning of a trend.
A pattern in properties, such as an increase or decrease.
What happens when an atom loses an electron?
It becomes positive
How many oxygen atoms are in CO₂?
2
What is the name of the element with the symbol H?
Hydrogen
What is the symbol for oxygen?
O
Define the meaning of an chemical symbol.
A one-or-two letter code for an element that is used by scientists in all countries.
Where are protons found?
in the nucleus
What is H₂O called?
Water
Hydrogen
What does CO₂ tell you about the atoms?
1 carbon atom and 2 oxygen atoms
Define the meaning of mass number.
The number of protons plus neutrons in the nucleus of an atom.
Is atoms the smallest cell
yes
What is an example of a compound?
(e.g. NH3, H2SO4)
What is the definition of Element
Substance that all other materials are made up of, and which contain only one type of atom. They cannot be broken down into other substances.
What is the chemical symbol for hydrochloric acid?
What is HCI?
Define the meaning of atomic mass
The average mass of an element accounting for the different forms in which it is found