The fire emoji represents a streak. A streak in snapchat is defined as three days in a row in which you and a friend snap eachother. The number next to the streak tells you how many consecutive days you and a friend have snapped eachother. The fire emoji streak will appear when you have snapped three days in a row. Once you have started a streak the goal is to keep the streak alive for as long as possible.
In an atom of gold, there are 79 protons and 79 electrons. The number of neutrons for gold may vary by isotope. In an atom of gold, there are 79 protons and 79 electrons. The number of neutrons for gold may vary by isotope.
A community for students. A proton (mass 1 amu) is shot at a speed of 5.0 x 10^6 m/s toward a gold target. The nucleus of a gold atom (mass 197 amu) repels the proton and deflects it straight back toward the source with 90% of its initial speed. What is the recoil speed of the gold nucleus? v_gf = m_pâv_piâ(1-r_vp)/m_g = (1 amu)â(5.0Ã10â¶ m/s)â(1-(-0.90))/(197 amu) = 4.8223Ã10â´ m/s v_gf = (1 amu)âv_piâ(1-(-0.90))/(197 amu) = (1.9/197)âv_pi = 0.009645âv_pi ... including the initial state of the gold atom: v_gf = v_gi+(m_pâv_pi+m_gâv_gi-m_pâv_piâr_vp)/m_g.