Physical Science Practice 1 First 9 Weeks

What do you call an atom of the same element with a different number of neutrons?

• Ion

• Metal

• Isotope

• Radioactive element

Answer explanation

An atom with the same number of protons but a different number of neutrons is called an isotope. This means isotopes of an element have the same chemical properties but different mass numbers.

A certain atom has 26 protons, 26 electrons, and 30 neutrons. What is the mass number of this atom?

• A. 26

• B. 30

• C. 52

• D. 56

Answer explanation

The mass number is the sum of protons and neutrons. Here, there are 26 protons and 30 neutrons. Therefore, the mass number is 26 + 30 = 56. The correct answer is D. 56.

What is the group number for hydrogen in the periodic table?

• A. 1

• B. 2

• C. 3

• D. 4

Answer explanation

Hydrogen is located in Group 1 of the periodic table, which is the first column. This group includes alkali metals, and hydrogen, while unique, is placed here due to its similar valence electron configuration.

Which of the following is NOT a property of metals?

• A. Conductivity

• B. Malleability

• C. Brittleness

• D. Ductility

Answer explanation

Brittleness is not a property of metals; they are typically malleable, ductile, and good conductors of electricity. Brittleness refers to a material's tendency to break or shatter easily, which is characteristic of non-metals.

Which bond type makes compounds?

• Bond Type A

• Bond Type B

Answer explanation

Bond Type A is responsible for forming compounds through the sharing or transfer of electrons, while Bond Type B does not contribute to compound formation. Therefore, Bond Type A is the correct choice.

In which bond type are electrons transferred to result in a noble configuration?

• Bond Type A

• Bond Type B

Answer explanation

In Bond Type B, electrons are transferred between atoms, allowing them to achieve a noble gas electron configuration. This transfer is characteristic of ionic bonds, making Bond Type B the correct choice.

Which of the following is an example of Bond Type B?

• NaCl

• H2O

• CaCl2

• MgF2

Answer explanation

NaCl is an example of Bond Type B, which refers to ionic bonds. In NaCl, sodium (Na) donates an electron to chlorine (Cl), resulting in the formation of positively and negatively charged ions that attract each other.

What is one disadvantage of nuclear power?

• Renewable energy source

• Long-term waste management

• Low energy output

• High greenhouse gas emissions

Answer explanation

One major disadvantage of nuclear power is long-term waste management. The radioactive waste produced remains hazardous for thousands of years, posing significant challenges for safe storage and disposal.

Which of the following is a type of bond found in MgO?

• Covalent

• Ionic

• Metallic

• Hydrogen

Answer explanation

MgO (magnesium oxide) consists of magnesium and oxygen, where magnesium donates an electron to oxygen, resulting in the formation of charged ions. This transfer of electrons characterizes ionic bonding, making 'Ionic' the correct choice.

Identify the compound name for MgO.

• Magnesium Oxide

• Magnesium Hydroxide

• Magnesium Carbonate

• Magnesium Sulfate

Answer explanation

MgO is composed of magnesium (Mg) and oxygen (O). The correct compound name is Magnesium Oxide, as it directly reflects the elements involved. The other options refer to different compounds.