Gen Chem Day 1-2 need to knows

When metals lose electrons, what do they form?

They form positive ions known as cations

When non-metals gain electrons, what do they form?

They form negative ions known as anions.

What are the properties of Ionic Compounds?

They are formed on non-metals and metals; they generally have a high melting point; they’re good conductors of electricity when melted/dissolved in water; they’re usually high in amount and soluble in polar solvents; they exist as solid structures at room temp.

What are the properties of Covalent Compounds?

They’re formed only by non-metals; they have a generally low melting point; they’re poor conductors of electricity; they’re usually insoluble/poorly soluble; they can exist in any state at room temp.

What numbers that are not __ are significant?

Ex) 1.234 ; 1.237 ; 2.983

Which zeros in the middle of ___ numbers are significant?

Ex) 5.008 ; 7.309 ; 4.006

Why are the following not considered larger than 3 sig figs?: 00.378 and 0.0314?

They are not considered sig figs because they are called leading zeros. If a decimal starts with 0s, they won’t be significant until they are in between real numbers.

Why are the following not more than 1 sig fig?: 4,000 ; 7,000 ; 9,000?

This is because zeros that are present in a large, non-decimal number are not significant.

On the pH scale, a molecule that has acquired a proton is called what?

A Base

In the pH scale, a molecule that has lost a proton is called what?

An Acid.

What is a Covalent Bond?

This is when atoms/molecules share electrons equally (though they can still carry charges).

What is a Hydrogen Bond?

This is when atoms/molecules form a bond by opposite charges attracting (positive charges attract negative charges and vice versa).

What is a Polar Bond?

This is when electrons are shared unequally.

What is a Non-Polar Bond?

This is when electrons are shared equally; these bonds do not have a charge.