Midterm Flashcards

Front

What is the atomic number of carbon?

Back

6

Answer explanation

The atomic number of an element is defined as the number of protons in its nucleus. Carbon has 6 protons, which gives it an atomic number of 6. Therefore, the correct answer is 6.

Tags

NGSS.HS-PS1-1

Front

Which of the following elements is a noble gas? Oxygen, Nitrogen, Argon, Hydrogen

Back

Argon

Answer explanation

Argon is a noble gas, known for its lack of reactivity due to a full valence shell. In contrast, oxygen, nitrogen, and hydrogen are not noble gases and are more reactive.

Tags

NGSS.HS-PS1-1

Front

What is the chemical symbol for sodium?

Back

Na

Answer explanation

The chemical symbol for sodium is 'Na', derived from its Latin name 'Natrium'. The other options, 'S', 'N', and 'So', do not represent sodium in the periodic table.

Tags

NGSS.HS-PS1-1

Front

Which of the following is a chemical property of an element? Color, Density, Reactivity with acid, Melting point

Back

Reactivity with acid

Answer explanation

Reactivity with acid is a chemical property, indicating how an element interacts with acids. In contrast, color, density, and melting point are physical properties, describing the element's appearance and state.

Tags

NGSS.HS-PS1-2

Front

Which of the following elements is likely to form a cation? Chlorine, Oxygen, Sodium, Sulfur

Back

Sodium

Answer explanation

Sodium is an alkali metal that readily loses one electron to achieve a stable electron configuration, forming a cation (Na+). In contrast, chlorine, oxygen, and sulfur tend to gain electrons to form anions.

Tags

NGSS.HS-PS1-2

Front

Which of the following best describes the law of conservation of mass?

Back

Mass is conserved in a closed system.

Answer explanation

The law of conservation of mass states that in a closed system, mass cannot be created or destroyed, only transformed. Therefore, the correct choice is that mass is conserved in a closed system.

Tags

NGSS.HS-PS1-7

Front

Back

Answer explanation

The equation 2H_2 + O_2 → 2H_2O is balanced because it has 4 hydrogen atoms and 2 oxygen atoms on both sides. The other options do not have equal numbers of atoms for each element, making them unbalanced.

Tags

NGSS.HS-PS1-7

Front

Which of the following best describes the second law of thermodynamics?

Back

Energy tends to disperse and spread out.

Answer explanation

The second law of thermodynamics states that energy tends to disperse and spread out, leading to increased entropy in a system. This means energy naturally moves towards a more disordered state.

Tags

NGSS.HS-PS3-4

Front

Which of the following statements is true about the periodic table?

Back

Elements are arranged by increasing atomic number.

Answer explanation

The periodic table is organized by increasing atomic number, which reflects the number of protons in an element's nucleus. This arrangement allows for a systematic classification of elements based on their properties.

Tags

NGSS.HS-PS1-1

Front

Predict the product of the reaction between sodium (Na) and chlorine (Cl).

Back

NaCl

Answer explanation

The reaction between sodium (Na) and chlorine (Cl) forms sodium chloride (NaCl). Sodium has a +1 charge and chlorine has a -1 charge, resulting in a 1:1 ratio, making NaCl the correct product.

Tags

NGSS.HS-PS1-2