All of the elements in the periodic table are monoatomic except the 7 elements that are diatomic atoms. These 7 elements are hydrogen, nitrogen, oxygen, chlorine, bromine, iodine and fluorine. Monoatomic substances are those elements that are stable by themselves.
Answer:
5.46 8 x 10²³ molecules.
Explanation:
- <em>Knowing that every one mole of a substance contains Avogadro's no. of molecules (NA = 6.022 x 10²³).</em>
<em><u>Using cross multiplication:</u></em>
1.0 mole → 6.022 x 10²³ molecules.
9.08 x 10⁻¹ mole → ??? molecules.
∴ The no. of molecules of CO₂ are in 9.08 x 10⁻¹ mol = (6.022 x 10²³ molecules) ( 9.08 x 10⁻¹ mole) / (1.0 mol) = 5.46 8 x 10²³ molecules.
Where are the following elements to choose from?
<u>Answer</u>:
By tracking oxidation numbers we can identify the number electron in the atom
<u>Explanation</u>:
Tracking of electrons helps us to know when and how many electrons get transferred from one atom to other atom . Oxidation referred as the “loss of one or more electrons” by an atom. When the oxidation number of an element increases, there is a loss of electrons and that element is being oxidized. Oxidation numbers are usually written with the sign (+plus or −minus) followed by the magnitude, which is the opposite of charges on ions. In their elemental stage oxidation number of an atom is zero.
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
