Atoms, Elements and Compounds Flashcards
Chemical equations are always balanced. Explain why.
Because no atoms are lost during a chemical reaction.
Explain what the formula Na2CO3 shows about the compound
2 sodium
1 carbon
3 oxygen
Why is sodium chloride a compound?
Because there are two different types of atoms and elements.
Why is titanium an element?
Because it only contains one type of atom.
An atom of argon has 18 protons and 22 neutrons. Work out its atomic number and it’s mass number.
The atomic number is 18 and the atomic mass is 18 + 22 = 40.
Use ideas about electron arrangements to explain why the elements in Group 0 have similar properties.
The highest occupied energy level IMF each group 0 element contains 8 electrons. Because there are the same number of electrons in the highest occupied energy level of each group 0 element, the group 0 elements have similar properties.
How many elements join together to make the compound sodium chloride?
Two - sodium and chlorine
Use ideas about atoms to explain the difference between an element and a compound.
An element is made up of one type of atom only. A compound consists of atoms of more than one type.
Explain how sodium and chloride ions are formed when sodium chloride is made from its elements.
When sodium chloride forms from its elements, one electron is transferred from the sodium atom to the chlorine atom. This results in a sodium ion with a single positive charge, Na+, and a chloride ion with a single negative charge, Cl-.
Explain how the atoms in a carbon monoxide molecules are held together.
In carbon monoxide, electrons are shared between the carbon and oxygen atoms.
A molecule of sulphur trioxide consists of one atom of sulfur joined to three atoms of oxygen. Work out its formula.
SO3
The formula of potassium manganate (VII) is KMnO4. Explain what the formula tells is about this compound.
In potassium manganate (VII) (potassium permanganate), there are four atoms of oxygen and one atom of manganese for every one atom of potassium.
What is an atom?
The smallest part of an element which can enter into a chemical reaction.
What is a chemical formula?
A way of showing the elements that are present in molecules of a substance.
What is a compound?
A substance consisting of two or more elements chemically combined together.
