## Which atom in the pictured molecule will have the strongest partial positive charge?

In the given molecule of NH2CHRCO2H the ball and stick model gives an idea about the bonds arranged in this molecule. With the given information it is easy to identify that Carbon and Oxygen atoms in the double bond CO will have the strongest partial positive charges.

As the bond is that is first oxygen is attached to carbon by a double bond and another oxygen is attached by a single bond. So, when carbon is attached to oxygen which is more electronegative pulls the electron cloud towards itself and gives carbon a partial positive charge.

## When an atom loses an electron it becomes:

A. Cation
B. Anion
C. Either cation or anion
D. Neither cation nor anion

## How many neutrons are in an atom of mg-25?

In the atom of Magnesium 25, , there are 12 protons as the proton number is always equal to the atomic number. The molecular mass of Magnesium is 25. The neutron number is given by the formula Molecular mass- Proton number :  25-12=13. So, the neutron number is the magnesium atom is 13.

## How many valence electrons are in an atom of magnesium?

Magnesium has atomic number 12. Its electronic configuration is 2,8,2. Thus, it has 2 valence electrons. It loses its two electrons to get a stable or octet configuration. The number of valence electrons in an element can be identified by referring to the group it belongs to.

a) 2
b) 4
c) 3
d) 8

## What type of bond joins the carbon atom to each of the hydrogen atoms?

a. double (nonpolar) covalent
b. single (nonpolar) covalent
c. polar covalent
d. ionic

## Which of these relationships is true of an uncharged atom?

A) The atomic mass is equal to the atomic number.
B) The number of electrons is equal to the number of neutrons.
C) The number of protons is equal to the number of electrons.
D) The atomic mass is equal to the number of electrons

## Which of the following is not attached to the central carbon atom in an amino acid?

a. A central carbon
b. A fatty acid group
c. An amine group
d. An acid group