Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
Answer:
5230J
Explanation:
Mass (m) = 250g
Initial temperature (T1) = 25°C
Final temperature (T2) = 30°C
Specific heat capacity (c) = 4.184J/g°C
Heat energy (Q) = ?
Heat energy (Q) = Mc∇T
Q = heat energy
M = mass of the substance
C = specific heat capacity
∇T = change in temperature = T2 - T1
Q = 250 × 4.184 × (30 - 25)
Q = 1046 ×5
Q = 5230J
The heat energy required to raise the temperature of 250g of water from 25°C to 30°C is 5230J
Answer: 4.46 x 10^-4M
Explanation:
The pH of a solution is the concentration of hydrogen ion concentration in the solution. Mathematically, it is expressed as pH = -log(H+), where H+ is the concentration of hydrogen ion
On the pH scale, readings are from 1 to 14.
- pH values less than 7 are regarded as acidic. So, the solution with pH 3.35 is said to be acidic, and will produce hydrogen ions.
3.35 = -log(H+)
(H+) = Antilog (-3.35)
(H+) = 0.000446M
Place (H+) in standard form
(H+) = 4.46 x 10^-4M
Thus, the concentration of hydrogen ion in the solution with pH 3.35 is 4.46 x 10^-4M
Fungi cannot make their food from sunlight, water and carbon dioxide as plants do, in the process known as photosynthesis
Your going to have to take a picture or make a list of the substances so i know which are and are not a compound
