The answer for your question is the first one
Answer:
<em>2.085 x 10^-20 J</em>
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Explanation:
minimum energy required to produce photoelectric effect in chromium is given as hf = 7.21 x 10^-19 J
The work function of chromium Ф = 4.37 eV = 7.00151 x 10^-19 J
The minimum energy required to eject an electron from from a chromium metal E = ?
From E = hf - Ф
substituting values, we have
E = (7.21 x 10^-19) - (7.00151 x 10^-19)
E = <em>2.085 x 10^-20 J</em>
Answer:
Explanation:
Chemical properties of atoms relies solely on the number of electrons they contain, more particularly, the valence or outermost electrons in the orbit round the nucleus of an atom.
A neutral atom is one that has not gained or lost electron or even shared electrons with any other atom.
On close examination of how electrons are distributed in the orbits of an atom, we can know if an atom will gain or lose electrons in a reaction. This is very important in determining the chemical properties of an atom.
<span>The part of making a solution that always releases energy is the overall change in forming the solution. The answer is letter D. Although letters A, B and C can be viable answers but, it is not always the case. There are some substances that when you mix or separate them requires more energy or less energy. An example would be w</span>hen the formation (or enthalpy of formation) of carbon
dioxide is negative, it means that it releases heat to the surroundings. When
it releases heat to the surroundings, the reaction is exothermic. Another example is when you mix baking soda and muriatic acid, the resulting mixture is colder. When it is cold, it means that the reaction is endothermic. So the best answer is letter D.
Answer:
answers are in attachment
Explanation:
1. Synthesis Reaction: In this type of reaction multiple reactant combine to form a single product.
2. Decomposition Reaction: In this type of reaction single compound or reactant break down into new elements or compounds.
3. Replacement Reaction: In this type of reaction an element replace an element in a compound.
4. Even hydrogen is not a metal but it can act as metal in single replacement reaction.
5. In combustion reaction fuel react with oxygen and give heat and light that increase temperature of surrounding.
6. In in-complete combustion reaction fuel react with in-sufficient oxygen and give carbon monoxide and carbon in form of soot.
7. Base is a compound that liberate OH⁻ ion in water.
8. indicators have different color in acid and base depends on pH of the solution
9. Salt and water are the product of neutralization reaction
NaOH + HCl = NaCl + H₂O
10. The pH of neutral solution is 7.