Semester 1 midterms science

Which of the following properties is not a characteristic of the group 1 A(1) elements (alkali metals)

Most of them are liquids at room temperature

The group 8A (18) elements …

Do not react

Which of the following is a characteristic of nonmetals?

Mostly liquids and gases

What is the description of a subatomic particle?

A proton has a positive charge in a mass of approximately one amu

In an atom, the nucleus contains…

All the protons and neutrons

Valence electrons are located…

In the outermost energy level of an atom

The octet rule says that…

Adams lose, gain or share valence electrons to have eight valence electrons

In ionic compounds __, lose their valence electrons to form positively charged _

Metals, and cations

Which of the following is an example of a heterogeneous mixture?

1. Sand mixed with oil

2. Salt dissolved in water

3. Air

4. Coffee

5. Vinegar

Sand mixed with oil

Which of the following is an example of a chemical change?

1. Grinding pepper

2. Melting candle wax

3. Freezing water

4. Digesting a hotdog

5. Cracking an egg

Digesting a hotdog

In a molecule with covalent bonding __

Atoms are held together by sharing electrons

One mole of particles of any substance contains how many particles?

6.02×10²³

The following reaction is an example of a _____ reaction

2C₂H₆+7O₂ –> 4CO₂+6H₂O

Combustion

A number of valence electrons found in an atom is equal to…

It’s group number

The number of neutrons in an atom is equal to the….

Mass number - the atomic number

which one of the following elements forms two or more ions with different charges?

Fe

What is the mass percent of carbon in methane, CH4?

74.9%

Which of the following is a compound?

1. Mercury in a gauge

2. Salt in a shaker

3. Aluminum in a can

4. Gold in a ring

5. Titanium in a golf club

Salt in a shaker

Noble gases is in __ and are normally at room temperature

Group 18