The atomic number of an atom is determined by the number of protons present in the atom that is the atomic number and number of protons are same for an atom. It is unique for every atom.
Atomic mass: It is nearly equals to the sum of mass of subatomic particles present in the atom that is sum of proton and neutron.
Number of neutrons: in an atom, the number of neutrons are always equal to the number of protons. If the number of neutrons are different for a number of proton then it is said be an isotope of that atom.
Protons plus neutrons: Sum of number of protons and number of neutrons is said to be the mass number of that atom.
Hence, the atomic number is the number of protons.
Answer:
D i am prety shure
Explanation:
Answer:-D
Explanation:
Answer : The correct option is 2.
Explanation :
Number of protons = 7
Number of neutrons = 6
Number of electrons = 10
Protons are those which carries positive charge.
Electrons are those which carries negative charge.
Neutrons are those which do not carry any charge that means neutrons are neutral.
The net charge on an ion = Number of protons present in an ion + Number of electrons present in an ion
The net charge on an ion = (+7) + (-10) = -3
Therefore, the net charge on an ion is (-3).
Answer : The correct option is, 318.1 J
Solution :
The given chemical reaction will be,
In this reaction, X and Y are the reactants and W and Z are the products.
As we know that the energy remains conserved during the chemical reaction.
So,
Sum of energy of product = Sum of energy of reactant
Therefore, the amount of chemical energy of product Z contain will be, 318.1 J
Answer:
318.1 J
Explanation:
The reaction given is:
X + Y → W + Z
The chemical energy of the reaction (ΔU), is the variation of the chemical energy, so is the chemical energy of the products (UW and UZ) less the chemical energy of the reactants (UX and UY).
If the reaction loses the chemical energy, it must be negative, and the chemical energy that a substance contains, is positive.
ΔU = (UW + UZ) - (UX + UY)
-111.6 = (41.9 + UZ) - (199.3 +272.3)
-111.6 = 41.9 + UZ - 471.6
- UZ = - 429.27 + 111.6
-UZ = - 318.1
UZ = 318.1 J
B. ^23 V
C. ^23 Mn
D. ^51 Sb
E. ^51 V
Answer:
E. ^51 V
Atomic number (number of protons in the nucleus): 23
Atomic symbol (on the periodic table of the elements): V
Atomic weight (average mass of the atom): 50.9415
Density: grams per cubic centimeter
Phase at room temperature: Solid
Melting point: 3,470 degrees Fahrenheit (1,910 degrees Celsius)
Boiling point: 6,165 F (3,407 C)
Number of isotopes (atoms of the same element with a different number of neutrons): 2; one stable V-51; one radioactive V-50
Most common isotopes: V-51 (99.75 percent natural abundance)
B. He gave them names and properties and placed them in the table.
C. He created them in his laboratory and placed them in the table.
D. He ignored them, placing them in the table and shifting others when they were discovered. 2. Which of the following elements have properties similar to those of astatine (At)? A. F, Br, I B. Ar, S, P C. F, Ar, Ne D. Na, Mg, Al 3.What is true of the ionic size of the elements in a group as one moves from top to bottom in that group?
A. Ionic size stays the same within the group.
B. Ionic size does not vary in any predictable way within the group.
C. Ionic size decreases from top to bottom within the group.
D. Ionic size increases from top to bottom within the group.