Sci Flashcards
Which is a property shared by most molecular compounds?
low melting point
Which of the following does NOT indicate a chemical change?
Change in surface area
You can balance a chemical equation by changing the what?
Coefficients
A change in matter that produces one or more substances is called a what?
Chemical change
When an atom gains an electron, it becomes a
Negative ion
When an atom loses an electron, it becomes an
Positive ion
Magnesium bromide is an ionic compound with the chemical formula MgBr2. What does the 2 tell you?
There are two bromide ions for every magnesium ion
In the chemical formula for an ionic compound, which item is written first?
The name of the positive ion
The chemical name for the compound with the formula Na2S is
Sodium sulfide.
Electrons involved in bonding between atoms are
Valence electrons
In chemical reactions, what does the principle of conservation mean?
Matter is not created or destroyed.
Which of the following groups contain the most reactive elements
Alkali metals
Ionic compounds that dissolve water conduct electricity because they break into _______ that move freely.
Ions
In a chemical equation, the substances written on the right side of the arrow are called __________
Products
Molecular compounds that dissolve in water do not conduct electricity because no ________ are presents.
Charged particles.
Because the electron in a molecule of hydrogen fluoride (HF) are more strongly pulled toward the fluorine atom, the molecule is ____________
Polar
A reaction in which one element replaces another in a compound
Replacement
A chemical reaction May be detected by observing changes in the properties of matter
True
Orderly crystal shapes, high melting points, and electrical conductivity when dissolved in water are properties of ionic compounds
True
When electrons are transferred between two atoms, a covalent bond is formed.
False
A low melting point is one property of molecular compounds
True
A non polar bond is formed when two atoms share electrons equally
False
Covalent bonds —->
Ionic Bonds —>
Share electrons
Transfer electrons
How do valence electrons relate to the chemical reactions of an element?
Valence electrons are used to form chemical bonds, in a chemical reaction valence electrons are used to form new substances
