Answer:
The symbol of isotopes used for blood flow analysis is 
<u>Explanation:
</u>
- Isotopes are the substances that exhibit the same atomic number but has a different mass number of an element.
- The atomic number explains the number of protons present in the element and mass number explains the number of neutrons available in the element.
- For blood flow analysis, the isotope element is cerium-141 and it is used in the chemical examination of blood flow particles.
- Symbol used for this isotope is
, where 141 indicates the amount of mass present and 58 indicates the proton number and 83 indicates neutron number present in that element.
- The amount of mass in an atom is calculated by the sum of protons and neutrons present in it. Thus mass of isotope is 141 obtained by the sum of 58 protons and 83 neutrons present in that isotope.
Answer:
D: Carbon
Explanation:
Carbon is the sixth element with a total of 6 electrons in the periodic table. Hence the atomic number Z = 6. The ground state electron configuration of carbon is 1s2 2s2 2p2. An excited state electron configuration of carbon is 1s2 2s1 2p3.
Answer:
4) Van der waals forces
Explanation:
Krypton (Kr) belongs to the noble gas group and has fully filled valence orbitals. In the solid phase, Kr exists as a white solid with a face centered cubic structure.
Intermolecular forces of attraction from the strongest to the weakest include:
Ionic > hydrogen bonding > dipole-dipole > london dispersion
Kr is monoatomic and non-polar. When fully filled (stable) valence orbitals of 2 Kr atoms approach each other in close proximity they experience a repulsive force which prevents the formation of strong bonds. Thus, the only force of attraction in Kr is the long range weak Van Der Waals force also known as the london dispersion force.
The swimming pools pH is below 7, meaning it is slightly acidic. If you want to make the pH higher, you must add a base which by definition has a pH higher than 7.
D. Add base
Answer:
A
Explanation:
Element A has 3 electrons in outermost shell so its valency is 3. It will loose 3 electrons to attain stability, as loss of 3 electrons is easier than gain of 5 electrons.
Valency of B is −2 as it will gain 2 electrons to attain stability and combine with other atom.
Valency of A⟶+3
Valency of B⟶−2
(Refer to Image)
Cross multiply valency of A and B
∴A2B3 compound will be formed.
