Chemestry Class

How many protons, neutrons, and electrons are present in an atom of Cadmium, Cd, with a mass of 112 amu?

• 48 protons, 112 neutrons, 64 electrons
• 48 protons, 160 neutrons, 48 electrons
• 48 protons, 64 neutrons, 48 electrons

Tags

NGSS.MS-PS1-1

An atom of a certain element has 36 protons, 36 electrons, and a mass number of 84.  At room temperature this element is a very stable gas.  How many neutrons are in this atom?

• 36
• 48
• 84

What type of particles are found in the cloud surrounding the nucleus?

• Positively charged particles and negatively charged particles.
• Negatively charged particles only.
• Neutral particles and positively charged particles.

What is the mass number of potassium (K) atom that has 20 neutrons?

• 18
• 20
• 39

An atom has 25 protons, 30 neutrons, and 25 electons.  What is the charge of the atom's nucleus?

• +25
• +30
• -25

The atoms of a certain element each contain 11 protons and 1 valence electron.  Which statement identifies this element and its chemical reactivity?

• The element is sodium, and it is highly reactive.
• The element is fluorine, and it is not reactive.
• The element is sodium, and it is not very reactive.

Tags

NGSS.HS-PS1-1

A chemist is identifying the elements present in a sample of seawater.  What characteristic of an element's atoms always determines the element's identity?

• The number of neutrons.
• The number of protons.
• The number of valence electrons.

The table below list three characteristics of an atom of an element.
An atom of which element is described by the data in the table?

• Radon (Rn)
• Cadmium (Cd)
• Rubidium (Rb)

Tags

NGSS.MS-PS1-1

A model of an atom is shown on your worksheet.  An atonm of which element is represented by this model?

• Boron (B)
• Carbon (C)
• Sodium (Na)

Tags

NGSS.MS-PS1-1

 Which two elements are in the same period?

• Sn and Rb
• F and Cl
• K and Ba