Answer:
D. It is a chemical reaction because the total mass remains the same when new substances are formed.
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen. The number of atoms are same on both side however arrangement of atoms is different.
While in case of nuclear reaction small change in mass take place.
Answer:
A synthetic element is one of 24 chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made".
Explanation: hope that helps
Answer:
d. the conjugate base of the weak acid
Explanation:
The strong base (BOH) is completely dissociated in water:
BOH → B⁺ + OH⁻
The resulting conjugate acid (OH⁻) is a weak acid, so it remains in solution as OH⁻ ions.
By other hand, the weak acid (HA) is only slightly dissociated in water:
HA ⇄ H⁺ + A⁻
The resulting conjugate base (A⁻) is a weak base. Thus, it reacts with H⁺ ions from water to form HA, increasing the concentration of OH⁻ ions in the solution.
Therefore, the resulting solution will have a pH > 7 (basic).
Which of these is an isoelectronic series? 1) na+, k+, rb+, cs+ 2) k+, ca2+, or, s2– 3) na+, mg2+, s2–, cl– 4) li, be, b, c 5) n
ss7ja [257]
An isoelectronic series is where all of the ions listed have the same number of electrons in their atoms. When an atom has net charge of zero or neutral, it has equal number of protons and electrons. Hence, it means that the atomic number = no. of protons = no. of electrons. If these atoms become ions, they gain a net charge of + or -. Positive ions are cations. This means that they readily GIVE UP electrons, whereas negative ions (anions) readily ACCEPT electrons. So, to know which of these are isoelectronic, let's establish first the number of electron in a neutral atom from the periodic table:
Na=11; K=19; Rb=37; Cs = 55; Ca=20; S=16; Mg=12; Li=3; Be=4; B=5; C=6
A. Na⁺: 11-1 = 10 electrons
K⁺: 19 - 1 = 18 electrons
Rb⁺: 37-1 = 36 electrons
B. K⁺: 19 - 1 = 18 electrons
Ca²⁺: 20 - 2 = 18 electrons
S²⁻: 16 +2 = 18 electrons
C. Na⁺: 11-1 = 10 electrons
Mg²⁺: 12 - 2 = 10 electrons
S²⁻: 16 +2 = 18 electrons
D. Li=3 electrons
Be=4 electrons
B=5 electrons
C=6 electrons
The answer is letter B.
Explanation:
When experimenting, the best hypothesis to develop would be a null hypothesis (H₀). A null hypothesis is a statement indicating no change or effect. In this case, it would be;
“There is no effect of temperature on the solubility of a solid in a liquid”
An alternative hypothesis (Hₐ) would be;
“There is an effect of temperature on the solubility of a solid in a liquid”
In this experiment, the null hypothesis would be rejected and the alternative would be accepted. This is because the experiment would show that increased temperatures of the liquid increases solubility of the solid in the liquid.
